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Traffic Analysis Toolbox Volume V:

Traffic Analysis Tools Case Studies

Benefits andApplicationPUBLICATION NO. FHWA-HOP-06-005 November 2004

Office of Operations

1200 New Jersey Avenue, SE

Washington, DC 20590

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Foreword Traffic Analysis Tools Case Studies

Foreword

Traffic analysis tools is a collective term used to describe a variety of software-based analytical procedures and methodologies that support different aspects oftraffic and transportation analyses. Traffic analysis tools include methodologies

such as sketch-planning, travel demand modeling, traffic signal optimization, andtraffic simulation. The purpose of this document is to give the reader a summaryof real world case studies that demonstrate the benefits of using traffic analysistools for the project.

This document serves as the final installment of the Traffic Analysis Toolbox, butserves as a document that can be used with decision makers to support thetransportation professional. . Other volumes currently in the toolbox include:Volume I: Traffic Analysis Tools Primer, Volume II: Decision SupportMethodology for Selecting Traffic Analysis Tools and Volume III: Guidelines forApplying Traffic Microsimulation Modeling Software.

The intended audience for this report is the transportation professional or managerwho needs a high-level introduction into the role of traffic analysis tools in thetransportation analysis process.

Jeffery A. Lindley, P.E.DirectorOffice of Transportation Management

Kittelson & Associates, Inc. 1

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportationin the interest of information exchange. The U.S. Government assumes no liability for the useof the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks ormanufacturers names appear in this report only because they are considered essential to theobject of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serveGovernment, industry, and the public in a manner that promotes public understanding.Standards and policies are used to ensure and maximize the quality, objectivity, utility, andintegrity of its information. FHWA periodically reviews quality issues and adjusts its programsand processes to ensure continuous quality improvement.

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Foreword Traffic Analysis Tools Case Studies

Technical Report Documentation Page

1. Report No.FHWA- HOP- 06- 005

2. Government Accessi on No. 3. Reci pi ent ' s Catal og No.

5. Repor t DateNovember 2004

4. Ti t l e and Subt i t l eTr af f i c Anal ysi s Tool box

Vol ume V: Traf f i c Anal ysi s Tool s Case St udi es -Benef i t s and Appl i cat i ons 6. Per f ormi ng Or gani zat i on Code

7. Aut hor ( s)

Pr i nci pal I nvest i gat or : Wayne Ki t t el son, P. E.Co- Author s: Peter Koonce, Soni a Hennum, Sagar Onta, andTi m Lut t r el l

8. Per f ormi ng Or gani zat i on ReportNo.

Proj ect 6115

10. Work Uni t No. ( TRAI S)9. Perf ormi ng Or gani zat i on Name and Addr ess

Ki t t el son & Associ at es, I nc. ( Lead Per f or mi ngOr gani zat i on)610 SW Al der St r eet , Sui t e 700

Por t l and, OR 97205 U. S. A.

Sci ence Appl i cat i ons I nt er nat i onal Cor por at i on ( SAI C)( Pri me Cont r act or)1710 SAI C Dr i veMcLean, VA 22102

11. Cont r act or Gr ant No.

DTFH61- 01- C- 00180

13. Type of Repor t and Peri odCoveredI nf ormat i onal Gui de Book

Mar ch 2004 t o November 2004

12. Sponsor i ng Agency Name and Address

Federal Hi ghway Admi ni st r at i onOf f i ce of Operat i ons, HOTM1200 New J er sey Avenue, SEWashi ngton, DC 20590

14. Sponsor i ng Agency Code

15. Suppl ement ary Not esJ ohn Hal ki as and J ohn Tol l e wer e t he Techni cal Represent at i ves f or t he Federal Hi ghwayAdmi ni st r at i on.

16. Abst r act"Traf f i c anal ysi s t ool s" i s a col l ecti ve term used t o descri be a var i et y of sof t war e- basedanal yt i cal pr ocedur es and met hodol ogi es that support di f f erent aspect s of t r af f i c andt r anspor t at i on anal yses. Tr af f i c anal ysi s t ool s i ncl ude met hodol ogi es such as sket ch-pl anni ng, t r avel demand model i ng, t r af f i c si gnal opt i mi zat i on, and t r af f i c si mul at i on. Thepur pose of t hi s Traf f i c Anal ysi s Tool box i s t o gi ve t he reader a summar y of r eal worl d casest udi es t hat demonst r at e the benef i t s of usi ng t r af f i c anal ysi s t ool s f or t he pr oj ect.

17. Key Wor d

Tr af f i c Anal ysi s Tool s

18. Di st r i but i on St atement

No Rest r i cti ons.

19. Securi t y Cl assi f . ( oft hi s report )Uncl assi f i ed

20. Securi t y Cl assi f . ( oft hi s page)Uncl assi f i ed

21. No. ofPages

28

22. Pri ce

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized


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1.0 Introduction Traffic Analysis Tools Case Studies

1.0 Introduction

Traffic analysis is an essential and complex component of planning, building,and operating our transportation system infrastructure. There are many differentanalysis tools to aid in these analyses, each of which has been designed with a

particular need in mind1

. Used correctly, these tools provide answers in clear andsufficient detail to inform decision-makers about the likely effects, both positiveand negative, of alternative solutions. The Traffic Analysis Toolbox helps you andyour staff select the right tool for each job, so important investment decisions aremade consistently and without delay.

Read through the following pages to learn about real-world examples of what canbe achieved when the analysis methods described in the Traffic Analysis Toolboxare correctly applied. Altogether, these case studies show how different types oftools have been effectively applied to the wide range of problems that confrontevery community and agency. You can use the chart below to find the type and

level of analysis that is of most interest to you.


1See, for example, Volume I: Traffic Analysis Tools Primer, available athttp://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/tat_vol1/default.htm ,for an overview ofthe full range of traffic analysis tools available today.
http://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/tat_vol1/default.htmhttp://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/tat_vol1/default.htm

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2.0 Community Benefits Traffic Analysis Tools Case Studies

2.0 Community Benefits

A safe and efficient multimodal transportation system is important for assuring astrong and vibrant community. It is vital to economic development and quality oflife. At the same time, the investment costs required to plan, build, manage, and

maintain the necessary physical elements is very high. So it is important forelected officials and transportation decision-makers to have access to reliable,consistent, and clear information about system impacts when they are makingchoices between competing investment opportunities.

A wide range of traffic analysis tools is available toassist in this purpose. But there is no clear guidanceabout how best to organize and use these tools in away that reliably, consistently, and clearly supportsthe transportation decision-making process. TheTraffic Analysis Toolbox, developed by the Federal

Highway Administration, organizes these toolsaccording to the types of problems and levels ofanalysis to which they are best suited so that theobjectives of reliability, consistency, and clarity canbe achieved.

The case studies presented in Chapters 3, 4, and 5 document how variouscommunities have solved real problems efficiently and effectively by applyingavailable traffic analysis tools in the logical and efficient manner described in theTraffic Analysis Toolbox. Nine real-world experiences from across the UnitedStates show how application of the right traffic analysis tools at the right stage ofthe analysis saved time for both the projects and the engineers, identifyingeffective ways to maximize the capabilities of the existing physical infrastructurealong the way and directing scarce investment dollars toward projects with themost community benefit:

Labor Hour Comparison

0

200

400

600

800

Sketch

Planning

HCM Method Simulat ion

o

a

ours

In Juneau, Alaska, sketch planningtraffic analysis tools helped achievecommunity consensus by quicklyand clearly highlighting the lane andinterchange requirements associatedwith different alternatives.


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2.0 Community Benefits Traffic Analysis Tools Case Studies

In Tualatin, Oregon, the right combination ofHighway Capacity Manualmethods and other analytical models identified a signal timing and roadrealignment strategy that saved millions of dollars in freeway interchange

improvements while still accommodating the economic redevelopment ofa nearby area.

In Lee County, Florida, the use of trafficoptimization analysis tools resulted in newtiming plans for over 100 signals that reducedaverage peak-hour delays by over 15 percentand saved motorists more than $9 millionannually in time, fuel, and vehicle wear.

Clearly, the right application of traffic analysis toolsbenefits not only the engineers and planners who use

them, but also the communities and decision-makersthey serve. The Traffic Analysis Toolbox includes anexpert system to help make these choices: by answeringa few questions about key project characteristics, theexpert system will suggest the type of traffic analysistool to get you to clear, complete, and consistentanswers that are necessary for making sound transportation investment decisionsin your community. Whats even better, this expert system is freely available fromthe Federal Highway Administration. It should be a part of every transportationagencys toolbox, and it can be found at:

http://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htm

While other volumes of the Toolbox provide more specific guidance related to thetechnical aspects of selecting the right tool, this volume provides insight into thebenefits achieved through identifying and using the appropriate traffic analysisprocedures and tools.

http://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htmhttp://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htmhttp://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htm

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3.0 Regional Transportation Plans and Programs Traffic Analysis Tools Case Studies

3.0 Regional Transportation Plans and Programs

Large-scale planning efforts will clearly benefit from using the right trafficanalysis tools. The questions to be answered in these efforts are basic ones: shouldthe roadway be treated as an expressway or an arterial? How many lanes will be

required? Whats the best form of control for the intersections? Speciallydesigned traffic analysis tools focus in on the answers to these questions withoutgetting lost in the costly and time-consuming detail of operational and designconsiderations that will come later. Many such tools have been developed and canbe effectively applied within the realms of sketch planning and travel demandmodeling. The table below introduces two real-world case studies presented in theremainder of this chapter to demonstrate the benefits that can be achieved throughthe proper application of traffic analysis tools in regional transportation plans andprograms.

Type of Analys is Real-World Case Study

3. 1 Sket ch Pl anni ngWest Egan Dr i ve Cor r i dor StudyJuneau, Alaska

3. 2 Tr avel Demand Model i ngCi t y- Wi de Transport at i on Syst emPl anTualatin, Oregon


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3.1 Sketch Planning Case StudyCorridor Refinement Study Traffic Analysis Tools Case Studies

3.1 Sketch Planning Case StudyCorridorRefinement Study

Sketch planning traffic analysis tools are often used in regional transportation

planning to analyze the impacts of regional growth trends on the transportationinfrastructure. These tools can quickly and effectively evaluate the adequacy ofroadway networks and intersections. As such, they also help in developingregional plans.

West Egan Drive Corridor Study - Juneau, AK

Key Benefits

Cl ear and adequat e i nf ormat i on t o f ormul at e al t er nat i ves

Less engi neer i ng t i me r equi r ed t han f or ot her t ypes ofanal ysi s

Equal consi der at i on of al l st akehol der pr oposal s t o bespeci f i cal l y consi der ed

Other Considerations

Out put f r om sket ch pl anni ng anal ysi s t ool s shoul d besuppl ement ed wi t h ot her more detai l ed anal ysi s pr ocedur espr i or t o f i nal desi gn and i mpl ement at i on concept desi gn

Minimum Data Required, Easy to Understand

Readi l y- avai l abl e dat a wer e al l t hatwas necessary t o appl y t he sket chpl anni ng t r af f i c anal ysi s t ool s. Modelout put s wer e al so ver y st r ai ght f orwar dand easy to under st and, r esul t i ng i nconsi st ent and ef f ect i ve communi cat i onof key f i ndi ngs wi t h deci si onmaker s and

Effective and Adequate Evaluation

J uneau s r egi onal goal ofbal anci ng mobi l i t y wi t h l ocalaccess needs was mor e easi l yeval uated by usi ng sket ch

pl anni ng t raff i c anal ysi s tool s,whi ch ar e i deal l y- sui t ed t o abroad- l evel assessment of manyi ndi vi dual i nt er sect i ons. A wi der ange of i deas and appr oacheswas suggest ed by busi nessowners, r esi dent s, and el ect edof f i ci al s, and t he sket chpl anni ng t raff i c anal ysi s t ool swere used t o qui ckl y documentt he maj or i mpacts of each.

By i dent i f yi ng l i kel y ar eas of


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3.1 Sketch Planning Case StudyCorridor Refinement Study Traffic Analysis Tools Case Studies

The use of the sketch planning traffic analysis tools provides basic intersectionvolume-to-capacity ratios and planning level intersection operational results.

With the help of these tools, numerous alternatives can be analyzed quickly andcost effectively. This allows alternatives to be discarded early in the process, with

more concentrated efforts of analysis on the most viable alternative. Hence, thesetraffic analysis tools ensure efficient use of limited project resources.

Stayed on ScheduleUse of t he sketch pl anni ngt raf f i c anal ys i s t oolr educed t he t i me necessaryt o sel ect vi abl eal t er nat i ves f or mor edet ai l ed anal ysi s. As ar esul t , t he pr oj ect was abl et o meet i mpor t ant deadl i nes

0

4

8

12

16

20

Sketch

Planning

HCM Method Simulation

Tim

etoComplete

(weeks)

Assisted in Dec is ion MakingProcess

J uneau s st af f were abl e t oscreen al t er nat i ves on t hebasi s of t he sket ch pl anni ngt raff i c anal ysi s resul t s byconsi der i ng t heef f ect i veness of t hepr oposed al t er nat i ve i n

conj unct i on wi t h theant i ci pat ed cost s. Thei nf easi bl e al t ernat i ves f roma cost or obj ect i vest andpoi nt were di scardedt hr oughout t he pr ocessbef ore more detai l edanal ysi s was compl et ed. Moredet ai l ed eval uat i on wasunder t aken onl y af t er f our


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3.2 Travel Demand Modeling Case Study Regional Plan Refinement Traffic Analysis Tools Case Studies

3.2 Travel Demand Modeling Case Study RegionalPlan Refinement

Aregional travel demand model was used to help create a blueprint for the futuretransportation system in Tualatin, Oregon. Travel demand models are especially

useful for this kind of activity because they take clear and direct account of thekey factors that can be managed and controlled population, employment, landuse, and system characteristics. Alternative growth visions for the communitywere evaluated according to their impacts on congestion and quality of service.

Transportation System Plan (TSP) - Tualatin, OR

Key Benefits

Pr edi ct ed how Tual at i n s t r anspor t at i on syst em wi l l beaf f ected by l and use, demogr aphi cs, and syst em i mpr ovement s.

Document ed and quant i f i ed t he benef i t s of f ut ur e i mprovement s.


Thi s t ype of model shoul d be r egul ar l y updated and cal i brat ed.


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3.2 Travel Demand Modeling Case Study Regional Plan Refinement Traffic Analysis Tools Case Studies

Travel demand models can also be used to predict the traffic-related effects ofalternative transportation policies and projections. Their ability to quantify theimpacts of a particular policy or proposed improvement on congestion,infrastructure investment requirements, access to all modes, and quality-of-lifeissues can help to inform the decision-making that leads to the final adopted plan.

Travel demand models do not work at a level of detail that is sufficient to designand construct the identified improvements, but they provide the essential inputother traffic analysis tools will need when the design effort is underway.

Subarea AnalysesTual at i n needed t o conduct a mor edet ai l ed eval uat i on of sever alsubareas wi t hi n t he ci t y where zonechanges were bei ng cont empl at ed.

The t r avel demand f or ecast i ng modelwas used t o wi ndow i n on t hesesubareas f or a more ref i nedanal ysi s. Usi ng t hi s t echni que, t heCi t y was abl e to eval uat e the l ocal

Informed decision makersTual at i n s key deci si on- makers( Ci t y Counci l and Pl anni ngCommi ss i on) wer e kept updat edt hr ough r egul ar br i ef i ngs t hati ncl uded col or f ul gr aphi csf r om t he t r avel demand model ,

showi ng t he ef f ect s of var i ouspol i cy opt i ons on keyper f ormance measures l i ker oadway vol ume and congest i on


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4.0 Project Development Traffic Analysis Tools Case Studies

4.0 Project Development

A wider range of tools with more detailed output capabilities is needed whentransportation-related projects move into the development stage. Here, the focus isusually on geometric considerations, operational characteristics, or both. The

practitioner will need access to a variety of analysis tools depending on accuracyand display-ability requirements of the audience. Many such tools have beendeveloped and can be effectively applied within the realms of sketch planning,design/operational analyses, and even simulation. The table below introducesthree real-world case studies used in the remainder of this chapter to demonstratebenefits that can be achieved through proper application of these tools in projectdevelopment environments.


4. 1 Sket ch Pl anni ng

Car man/ Quar r y/ MeadowsI nt er sect i on Layout andRoundabout Anal ysi sLake Oswego, Oregon

4. 2 Oper at i onal / Desi gnEval uat i on

Br i dgeport Vi l l age Shoppi ngCenter Devel opmentTualatin, Oregon

4. 3 Si mul at i on Anal ysi s andDi spl ay

K St r eet Busway Transi t

Al t er nat i ves Anal ysi sWashington, DC


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4.1 Sketch Planning Case Study Intersection Layout and Roundabout Analysis Traffic Analysis Tools Case Studies

4.1 Sketch Planning Case Study IntersectionLayout and Roundabout Analysis

Sketch planning traffic analysis tools were used to develop design alternatives toaddress both operational and safety issues at the Carman/Quarry/Meadows

intersection in Lake Oswego, Oregon. Using only basic turning volumeinformation, the tools predicted the number and configuration of lanes requiredfor different types of intersection control. This approach saved substantial timeand money, and laid the groundwork for the final design activities.

Carman/Quarry/Meadows Intersection Lake Oswego, OR

Key Benefits

Dat a requi r ed i s mi ni mal and r eadi l y avai l abl e i n most cases

Al l owed f or t he consi der at i on of mul t i pl e al t er nat i ves i n at i me and cost ef f i ci ent manner


Sket ch pl anni ng pr oduct s can gi ve deci si on makers anunderst andi ng of t he bi g pi ct ur e, even t hough modi f i cat i onsand gr eat er det ai l i s somet i mes necessary t hr ough detai l eddesi gn.

Context Appropriate Alternatives

The nei ghborhood and adj acentproper t y owner s key concerns weref ocused on envi r onment al ,accessi bi l i ty , l i vabi l i ty , andsaf et y i ssues, as opposed to pur ei nt ersecti on t raf f i c oper at i ons.As such, consi der at i on of t hesur r oundi ng syst em, and adj acentl and uses was r equi r ed t o devel op

Designing the Intersection

Sket ch pl anni ng of i nt er sect i oni mprovement s hel ped the publ i cvi sual i ze t he var i ous scenar i osbei ng consi der ed f or i mpr ovi ngsaf et y at an al l - way stopcont r ol l ed i nt er secti on. The

sket ches i l l ustr at ed speci f i ci mpact s t o adj acent pr oper t i esand wer e the f i r st st ep t owar dsi dent i f i n a r ef er r ed

StudyI nt ersecti


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4.1 Sketch Planning Case Study Intersection Layout and Roundabout Analysis Traffic Analysis Tools Case Studies

Aer i al photogr aph

Exi sti ng r i ght - of - way l i mi t s

Minimum Data Required

Sket ch pl anni ng al l ows f or ef f i ci entdevel opment and compar i son of

pr oj ect al t er nat i ves, gi ven t hemi ni mal dat a and ef f or t r equi r ed.Typi cal l y, i t i s onl y necessary t ouse:

Relative Outputs

Wi t h t hi s basi c dat a, t he sket chpl anni ng t ool can det er mi ne:

Basi c geometr i c l ayout s

Magni t ude of r i ght - of - way needs

Proper t y/ envi r onment al i mpact s

Rel at i ve assessment of est abl i shedeval uat i on cr i t er i a

Time Effectiveness

Sket ch pl anni ng f aci l i t at ed t heal t er nat i ves eval uat i on and deci si on

maki ng pr ocess i n a t i me ef f i ci entmanner:

By reduci ng t he i ni t i al ef f orti nvol ved, t he deci si on on t hepr ef er r ed al t er nat i ve wascompl et ed i n mi ni mal t i me

For each al t er nat i ve, pot ent i al l yf at al f easi bi l i t y i ssues were

0

2

4

6

8

Time in

Months

With Sketch

Planning

Without Sketch

Planning

Time to Complete Project Design

By mi ni mi zi ng t he number of al t er nat i ves t aken t o ref i nedeval uat i on and desi gn, t her e was a cost savi ngs of approxi matel y35% i n en i neer i n and desi n f ees.

Cost Effectiveness

The sket ch pl anni ng t ool saved engi neer i ng t i me as unpromi si ngal t er nat i ves wer e i dent i f i ed and di scar ded i n t he ear l y st ages ofeval uat i on, wi t hout r equi r i ng det ai l ed exami nat i on or r ef i nement t of i nal st ages of desi gn i mpl ement at i on


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4.2 Operational/Design Case Study Traffic Impact Study Traffic Analysis Tools Case Studies

4.2 Operational/Design Case Study Traffic ImpactStudy

In the project development process, HCM and/or other analytical methodsprovide the kind of detailed analysis that is needed to make decisions such as

required number of travel lanes at intersections, length of queue storage requiredfor each turning movement based on signal timing assumptions, and assortedother details. The detailed analysis helps provide the technical support for a list ofimprovements required for project development.

Bridgeport Village Shopping Center Development, Tualatin, OR

Key Benefits

Est i mated t he i mpact of t he devel opment on t he t r anspor t at i onnet work

Consi der ed t he physi cal l ayout of i mpr ovement s i n concer t wi t h

t he anal yt i cal anal ysi s l ead t o a compr ehensi ve sol ut i on.Other Considerations

These procedures r equi r e an i t erat i ve appr oach r egar di ngassumpt i ons f or desi gn and operat i ons

Adequacy of AnalysisI n t he Br i dgepor t Vi l l agepr oj ect, a 466, 000 sq. f t .mi xed use devel opmentl ocat ed adj acent t o acongest ed i nterchange wasbei ng consi dered. The

anal yt i cal met hod pr ovi dedout put s t hat were adequat ef or eval uat i on of t hei mpact of t heal t er nat i ves.

The anal yt i cal met hodeval uat ed t he delay( l evel - of - servi ce) ,capacity ( vol ume- t o-capaci t y rat i o) andqueuing ( 95t h- precent i l equeue est i mates) at t he

Cost and Time Effecti veVar i ous si ngl e anddoubl e l i ne dr awi ngswere used to eval uat eal i gnment al t er nat i vesand hel p f ocus t heanal yt i cal anal yses.Queue i nt er act i ons

bet ween cl osel y spacedi nt er sect i ons wer ecar ef ul l y scr ut i ni zed i nt he anal yti cal model s,


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4.2 Operational/Design Case Study Traffic Impact Study Traffic Analysis Tools Case Studies

The analytical method can be data intensive and costly if numerous alternativeswith different volumes, geometry and signal timing scenarios are to be analyzed.Significant time and budget can be saved if only the most viable alternatives areanalyzed in detail.

Queue InteractionThe HCM procedures arei nsuf f i ci ent f oraddr essi ng i ssues r el at edt o cl osel y spacedsi gnal i zed i nt ersecti ons,

and so addi t i onalmodel i ng of queuei nt er act i on was used t oconf i r m assumpt i ons used

Improved UnderstandingThe Br i dgeport Vi l l agepr oj ect benef i t ed f r omt he f ul l r ange of out putcapabi l i t i es t hat wer eavai l abl e. St andar dt abul ar out put served t odocument anal ysi s r esul t sand quant i f y key desi gnpar amet ers t hat woul d benecessary i n thesubsequent desi gn ef f or t .Vi sual ani mat i on was

usef ul t o bot h t heengi neers ( who used i t t oconf i rm t her easonabl eness of i nput

Pedestrian ConsiderationThe HCM procedures

addr ess i ssues r el at ed t opedest r i an t i mi ng needsat si gnal i zedi nt er secti ons, whi ch i san of t en- over l ookedi ssue. I n t hi s case,pedest r i an t i mi ng needswer e i ncl uded i n theanal si s and cal cul at ed


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4.3 Traffic Simulation Model Case StudyTransit Alternatives Analysis Traffic Analysis Tools Case Studies

4.3 Traffic Simulation Model Case StudyTransitAlternatives Analysis

The K Street Busway Study assessed a proposed busway that included transitservice planning and detailed simulation analysis. Simulation was used to

determine the effects of street reconstruction on all modes, to contrast thealternatives, and to determine a recommended solution that met the Cityspolicies.

Clear communication of the projectThe busway provi ded excl usi ver i ght - of - way f or buses t hr oughoutt he corr i dor . Ani mat i on was usedt o communi cat e t he nat ure of t hechanges t o t he cor r i dor t o thepubl i c. Pr oj ect engi neer si ndi cat e t hat t he vi sual i zat i onsi ni f i cant l i m r oved r o ect

Assessment of alternati vesThe proj ect eval uatedal t er nat i ves t o i mpr ovet he person car r yi ngcapaci t y f or t he KSt reet cor r i dor i nWashi ngt on, D. C. Transi tser vi ce al t er nat i veswer e t est ed t o i nsur et he person car r yi ngcapaci t y of t he buswaywas maxi mi zed and the

Det ai l ed i nf ormat i on i s needed on desi gn and oper at i onalcharact eri st i cs

Ef f i ci ent communi cat i on of pr oj ect out comes t o st akehol der sand deci si on maker s


K Street Busway - Washington D.C

Key Benefits

Eval uat i on of i mpact s on al l modes over several scenar i os


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Microsimulation can assess a much wider range of issues present in the corridorincluding effects to general automobile traffic, pedestrians, and existing andproposed bus service. This allows for decisions to be made while considering allmodes.

Another important dimension of this project is the complexity of the analyses thatwas performed. As a dense urban area, pedestrian interaction throughout theboulevard required careful consideration of the interaction of pedestrians andvehicle movements that are rarely encountered.

Pedestrian Interaction

Pedest r i an i nt er act i onwi t hi n t he boul evar dwas car ef ul l yconsi der ed i n t hepr oj ect because accesst o tr ansi t wasi mport ant t o thepubl i c. Pedest r i an

accessi bi l i t y t ot r ansi t was ani mpor t ant el ement i n

Sufficient analysis of aboulevard

A boul evard i s a compl exconf l uence of movement s( t r af f i c and ot her wi se) ,whi ch coul d not beef f ect i vel y anal yzed usi ng

t he HCM procedur e f or urbanst r eet s. El ement s of sket chpl anni ng met hods were usedt o det er mi ne appr opr i at et r eat ment s of si gnalpr i or i t y, but t he si mul at i on

Microsimulation

Mi cr osi mul at i on pr ovi ded anout put f or assessi ng t hecapaci t y of a busway undera var i et y of scenar i os,whi ch l ead t o modi f i cat i onst o a t r ansi t ser vi ce pl an

and t r anspor t at i on capaci t ycal cul at i ons.


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5.0 Operational Assessments Traffic Analysis Tools Case Studies

5.0 Operational Assessments

Traffic analysis tools that can answer detailed operational questions should be inthe toolbox of any practitioner who needs to get the most in capacity andperformance out of the existing system. The answers these tools provide can

guide the engineer and system owner toward effective solutions where expensiveand significant changes to the system are just not possible. They do this byanswering the detailed questions that usually control individual operationaldecisions: what signal phasing strategy will maximize capacity and minimizequeuing? How is a tolling/inspection station best operated to maximize itsthroughput? Can an arterial signal system promote transit ridership and still meetthe needs of other road users? What can be done to increase average travel speedsin an entire surface street network without building new roads or making anymajor physical improvements? A complete range of proven and fully-tested toolshas been developed, and which one to use in any particular situation depends onthe characteristics of the problem. The table below presents four case studies that

show how some of these tools were used in real-world situations to improveperformance and quality of service without the need for significant newinfrastructure investments.


5. 1 Sket ch Pl anni ngI nt erchange Anal ysi sEugene, Oregon

5. 2 HCM/ Anal yt i cal Model sQueui ng Anal ysi sFt. Hood, Texas

5. 3 Si mul at i on Model sTr ansi t Si gnal Pr i or i t yEval uat i onPortland, Oregon

5. 4 Tr af f i c Opt i mi zat i onSi gnal Ti mi ng Pl anFt. Myers, Florida


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5.1 Sketch Planning Case Study Interchange Analysis Traffic Analysis Tools Case Studies

5.1 Sketch Planning Case Study InterchangeAnalysis

Asketch planning traffic analysis tool can be an effective way to resolve signaltiming issues at interchanges. This type of tool does not need an extensive amount

of input data, and can be used to quickly and effectively evaluate such things asphase sequencing, number of approach lanes, and lane configuration at thesignalized intersections.

Qui ckl y i dent i f i ed t he reason f or l ong queues and t he r ange ofpossi bl e sol ut i ons

Used dat a t hat i s r eadi l y avai l abl e and easy to col l ect

Reduced anal ysi s t i me by 50- 70% compar ed t o a st andar d

oper at i onal anal ysi s procedur e


Thi s t ype of t r af f i c anal ysi s t ool provi des an overal lassessment of i nt er sect i on oper at i on ( under - , near - , or over -capaci t y) , but does not est i mat e t he i nt er sect i on l evel - of -servi ce.

Coburg Interchange Eugene, OR

Key Benefits

Pr oposedNew Si gnal

Exi st i ngSi gnal

Closely spaced signals lead toqueue spillback

The proposed new si gnalneeded t o be connect ed andcoordi nat ed t o t he exi st i ngsi gnal syst em wi t houti nt r oduci ng queui ng or cycl ef ai l ur es. The sket chpl anni ng t r af f i c anal ysi st ool was used t o desi gn ahasi n l an and l ane


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5.1 Sketch Planning Case Study Interchange Analysis Traffic Analysis Tools Case Studies

Sketch-planning traffic analysis tools only need data that are almost alwaysreadily available: hourly movement volumes, number of approach lanes, and lanecontrol. Even though sketch-planning traffic analysis tools are not detailedenough to use in final design, their output serves as essential input to other trafficanalysis tools that can be used for this purpose.

Eliminate Costly ImprovementsThe i nt er sect i ons al ong Cobur g Roadneeded t o meet mi ni mum vol ume- t o-capaci t y r at i o ( v/ c) t hr eshol ds.Sket ch pl anni ng t r af f i c anal ysi st ool s were abl e to meet t hi s need. As

a resul t , t he need f or a $1 mi l l i on

Sketch Planning ReducesStaff Time RequiredUsi ng sketch pl anni ngtr af f i c anal ys i s tool s ,t he Cobur g Roadi nt er sect i on anal yseswere compl et ed i n 25- 30

per cent of t he t i me t hatwoul d have been r equi r edi f the t r adi t i onalt raf f i c anal ys i s tool shad been appl i ed, and

Sufficient Data for a SolutionI nspect i on of t raf f i cvol umes at t he i nt erchangeshowed t hat t he exi st i ngcont r ol l er phasi ng( st ar t i ng and endi ng bothr amps t oget her ) r esul t edi n unnecessary congest i on.By el i mi nat i ng t hi sconst r ai nt , t he sout hboundar t er i al t r af f i c was fr eet o f i l l t he space bet weent he i nt er secti ons,


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5.2 HCM/Analytical Model Queuing Analysis Traffic Analysis Tools Case Studies

5.2 HCM/Analytical Model Queuing Analysis

Analytical models can be used in combination with more detailed analysisprocedures to provide a robust examination of complex situations. Deterministictools such as the HCM or other analytical models are effective ways to get

answers to some questions like lane control and queue space requirements. Theiroutput is relatively easy to understand and they also provide an efficient way tocompare and contrast alternatives.

Pr ovi ded vi sual conf i r mat i on of vehi cl e i ngr ess and egr esschar act er i st i cs under di f f er ent l ane conf i gur at i ons

Conf i r med i nf r ast r uct ur e needs

Demonst r ated t he need f or opt i mi zi ng checkpoi nt operat i ons and

r esour cesOther Considerations

These model s r equi r e moderat e t o detai l ed amount s of data t hatsomet i mes r equi r e si gni f i cant col l ecti on ef f or t .

Cal i br at i on of t he model s i s i mport ant t o ensur e they pr oduceconsi stent resul t s.

Security Screening Analys is Fort Hood, TX

Key Benefits

Clear and Consistent Results

The HCM procedure was used t o determi nean i ni t i al est i mat e f or queui ng based onmi l i t ar y st andar ds f or gat e pr ocessi ngt i mes f or sever al t hr eat condi t i onl evel s. Anal ysi s r esul t s wer e pr esent edi n an easy- t o- under st and t abul ar f ormatt hat cl earl y i dent i f i ed t he ef f ects ofdi f f er ent opt i ons on st af f i ngr equi r ement s and vehi cl e del ay.

Mi crosi mul at i on was subse uent l used f or

Consistent EvaluationChanges i n secur i t ypol i ci es r equi r ed aneval uat i on of t hesecur i t y checkpoi nt s att he Ar my base i n For tHood, Texas. Anal yseswere compl et ed toopt i mi ze checkpoi ntoperat i ons and mi ni mi zedel ays acr oss varyi ngt raf f i c condi t i onst hr oughout a typi calday. The t r af f i canal ysi s t ool pr ovi deda consi st ent f r ame of


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5.2 HCM/Analytical Model Queuing Analysis Traffic Analysis Tools Case Studies

The output from the analytical tools can also be used as input to microscopicsimulation models capable of a much more detailed analysis. For example,simulation allows visual confirmation of operating characteristics as well asexamination of more detailed issues.

Base personnel used the traffic simulation model to support presentations tomilitary officers and other key stakeholders. Ultimately, the simulation model wasused to support full, detailed design of access control points.


Effective Use of Several ToolsThi s proj ect benef i t eds i gni f i cant l y f rom t hesequent i al appl i cat i on of t wodi f f erent l evel s of t r af f i canal ysi s t ool s. The anal yt i calmodel pr ovi ded basi c i nsi ght si nt o si zi ng i ssues such asnumber of l anes and number ofcheckpoi nt s. The si mul at i onmodel pr ovi ded vi sualconf i r mat i on of oper at i ngchar act er i st i cs and al l owed

Development of Cost Effective SolutionsUsi ng t hese t r af f i c anal ysi s t ool s, l aneconf i gur at i ons wer e devel oped f or use i ndet er mi nat i on of st af f i ng l evel s by t i meperi od. Pr i or t o t he anal ysi s, st af f i ngl evel s wer e over est i mat ed and resul t ed i nneedl ess costs t o t he agency.

0

1

2

3

4

5

6

7

8

0000 to 0500 0500 to 0900 0900 to 1400 1400 to 2400

Time Period

NumberofStaffedLan

es

Before After

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5.3 Traffic Simulation Model Case Study Transit Signal Priority Evaluation Traffic Analysis Tools Case Studies

5.3 Traffic Simulation Model Case Study TransitSignal Priority Evaluation

Microsimulation was the appropriate tool to evaluate the effects of transit signalpriority strategies on traffic flow along major arterial corridors in Portland,

Oregon. This is because it was able to predict important performance measuresthat other analysis tools could not including, for example, vehicle delay andboth on-time performance and travel time variability for various levels of busservice. Its ability to illustrate the effects of alternative control strategies throughanimation was a very effective way for engineers and decision-makers alike toassess the overall system performance characteristics.

Quantifying key parametersBy t r acki ng t he movement ofeach vehi cl e i ndi vi dual l y,mi cr osi mul at i on can gi ve t hedeci si on maker a handl e oni mport ant consi der at i ons t hatot her anal ysi s t ool s cannot

consi der at i ons l i ke t heamount of t r avel t i me

Designing the systemMi cr osi mul at i on al l owedt he syst em desi gn t o be

f i ne- t uned t o meet t heCi t y of Por t l and sneeds. Bus st opl ocat i ons, st op ser vi ceper cent age, t r af f i ccondi t i ons, and si gnalt i mi ng st r at egi es wer evar i ed t o i sol at e t heef f ects of i ndi vi dualel ement s on t he TSPsyst em, and t hen t he

Transit Signal Prior ity - Portland, OR

Key Benefits

Demonst r at ed how bus t r avel speed can be i ncreased wi t hout

s i gni f i cant ef f ect s on t raf f i c f l ow Document ed and quant i f i ed i mport ant oper at i onal det ai l s

( queues, del ay, et c. )


Ef f ect i ve use of mi crosi mul at i on requi r es i nvest ment i n dat acol l ecti on and cal i brati on.


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5.3 Traffic Simulation Model Case Study Transit Signal Priority Evaluation Traffic Analysis Tools Case Studies

Hardware-in-the loop

Hardware- i n- t he- l oop uses acombi nat i on of si mul at i on sof t war e

and f i el d si gnal cont r ol l er equi pmentt o eval uat e t r af f i c condi t i ons i n anof f i ce set t i ng pr i or t o f i el di mpl ement at i on. Usi ng t hi s t echni quer educes di sr upt i ons f or t r af f i c andt r ansi t dur i ng i nst al l at i on andal l ows anal ysi s t o quant i f y t he

VISSIM Simulation 170 Traffic Controller

Controller Interface Device

Sufficient assessment ofstrategiesUse of si mul at i on i nsur edt hat l i mi t at i ons of t hef i el d hardware were

addressed and r esol vedpr i or t o i mpl ement at i on.

Thi s appr oach r educed t heamount of st af f t i me i nt he f i el d r equi r ed t oi mpl ement t he st r ategy,

Effects of variabilityPer f or mance of t he si gnal pr i or i t ysyst em i s dependent on t hecont r ol l er set t i ngs and t r ansi toper at i ons. Reduci ng t r avel t i me

var i abi l i t y i s a key t o i mpr ovi ngon- t i me perf ormance f or t r ansi t andsi mul at i on of el ement s such asboar di ng and tr af f i c i nt er acti onal l owed assessment of ke measures


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5.4 Traffic Optimization Case Study Signal Timing Plan Development and Implementation Traffic Analysis Tools Case Studies

5.4 Traffic Optimization Case Study Signal TimingPlan Development and Implementation

A traffic optimization tool was used when Lee County, Florida undertook theretiming of over 100 signals along 18 arterials, including 20 signals in downtown

Fort Myers. The tool was used to develop initial signal timing plans to minimizestops and delays to arterial through traffic. The plans were implemented and thenfine-tuned in the field.

Tool must f i r st be cal i brat ed t o f i el d condi t i ons t o ensuret he devel opment of r eal i st i c per f ormance expect at i ons

I mpr oved qual i t y of servi ce t o r oad users


Key Benefits

Ef f i ci ent way t o test mul t i pl e scenar i os and st r at egi es

Countywide Signal Retiming - Fort Myers, Florida

Development of OptimizationStrategies

The model was used t o assessexi sti ng t r af f i c condi t i ons aswel l as devel op new si gnalt i mi ng pl an opt i ons f or eachcor r i dor ( 6- 10 pl ans per

Testing of Multiple ScenariosDue t o t he seasonalf l uctuat i on i n t raveldemand, t wo set s of f i nalt i mi ng pl ans ( peak and of f -peak season) had t o bedevel oped and i mpl emented


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5.4 Traffic Optimization Case Study Signal Timing Plan Development and Implementation Traffic Analysis Tools Case Studies

The traffic optimization tool allowed for the testing, evaluation, and refinementof multiple strategies for each scenario prior to field implementation. Visualoutputs that are available from this type of tool can be useful to engineers inaffirming the correctness of the input as well as in demonstrating the benefits ofthe new signal timing plans to others.

Benefits Achieved

Mor e ef f ect i ve use of engi neer st i me

Average peak- hour del ays werer educed by 16% and st ops werer educed by 22%.

Easi er f i el d i m l ement at i on

Time Efficiency

0

20

40

60

80

100

120

With Tool Without Tool

StaffTime(hours)

Assistance in ImplementationFi el d i mpl ement at i on was madeeasi er t hr ough t he tool sabi l i t y t o creat e si gnalt i mi ng worksheets, t i me- spacedi agr ams, and f l ow pr of i l est hat were t hen used to

-

Efficiencies GainedUsi ng an opt i mi zat i ont ool gai ned bot h cost andt i me ef f i ci enci es bypr ovi di ng a means t o testand r ef i ne st r at egi es,pr i or t o f i el di mpl ement at i on. Thi smi ni mi zed t he amount ofst af f t i me spent i n t hef i el d, r educed t he amountof st af f t i me r equi r edover al l , and mi ni mi zed

Assistance in Decis ion ProcessThe opt i mi zat i on t ool hel pedi n maki ng key pr oj ectdeci si ons by t est i ng andeval uat i ng mul t i pl e


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6.0 What Next? Traffic Analysis Tools Case Studies


6.0 What Next?

Selecting the right traffic analysis tool for a project used to require the judgment,insight and knowledge that came only from years of experience and application.These continue to be important even today, of course, but now an expert system is

also available that makes the job considerably easier. By answering a fewquestions about key project characteristics, the expert system will suggest the typeof traffic analysis tool to get you to clear, complete, and consistent answers thatare necessary for making sound transportation investment decisions in yourcommunity. Whats even better, this expert system is freely available from theFederal Highway Administration; it should be a part of every transportationagencys toolbox, and it can be found at:

http://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htm.
http://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htmhttp://ops.fhwa.dot.gov/Travel/Traffic_Analysis_Tools/traffic_analysis_tools.htm

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