Traffic Calming: Introduction and Applications June 21st, 2007 by Indraneel Kumar, AICP

1. Transportation Planning and Traffic Calming- Part 2 Traffic Calming: Introduction and Applications June 21st, 2007 by Indraneel Kumar, AICP

2. Introduction What is Traffic Calming? Several definitions- ITE, VTPI, Source: VTPI.org • 3 Es- Education, Enforcement, and Engineering • Police enforcement-engineering • options- street closure • Management of traffic by volume • and speed • Part of “Context Sensitive Design” • Flexible design standards

3. History • 1960s first experiment commenced in Holland • 1970s- Implementation in Germany (Verkehrsberuhigung or Transportation Calming) • 1980s- Livable Streets by Appleyard, UC Berkeley • Institute of Transportation Engineer’s Guidebook • 1990s- Traffic Calming: State of the Practice, Reid Ewing, ITE • Thousands of Traffic Calming projects Control Speed; Control Volume; Control Volume / Speed

4. Applications: Traffic Calming to Control Speed Bulb-Out Source: www.pedbikeimages.org / Dan Burden • Bulbs, Chokers, Neckdowns are interchangeable terms • Extension of the curb and sidewalk to narrow the roadway • Physical constraint • Visual traffic calming effects • Pedestrian crossing Source: www.pedbikeimages.org / Dan Burden Bulb-Outs/ Curb Extensions/ Neckdowns

5. Applications: Traffic Calming to Control Speed Source: www.pedbikeimages.org / Dan Burden Choker Source: www.pedbikeimages.org / Michael King Chokers Source: Making Streets That Work • Extension of the curb and planting • Midblock or intersection corners • Parallel, angled chokers, etc. • Planting to alert the motorist • Physical constraint • Visual traffic calming effects

6. Applications: Traffic Calming to Control Speed Source: www.pedbikeimages.org / Michael King Source: www.pedbikeimages.org / Portland Office of Transportation • Chicanes- staggered curves • Alternate extension of the curb • Shift in alignment • Physical constraint • Visual traffic calming effects Source: www.pedbikeimages.org / Portland Chicanes Source: ITE

7. Applications: Traffic Calming to Control Speed Source: www.pedbikeimages.org / Mark Lavergne Source: www.pedbikeimages.org / Michael King • Cushions- Convenient for emergency vehicles Source: www.pedbikeimages.org / Dan Burden Speed Tables, and Cushions

8. Applications: Traffic Calming to Control Speed Source: PCRD / Kumar Speed Bumps and Humps Source: PCRD / Kumar

9. Applications: Traffic Calming to Control Speed Source: www.pedbikeimages.org / Dan Burden Source: www.pedbikeimages.org / Peter Lagerway Source: www.pedbikeimages.org / City of Portland Curb Radius, Raised Crossings and Intersections • Tighter curb radius • Raised crossing and intersection- alerts drivers • Paving treatment + Raised surfaces • Visual traffic calming effects

10. Applications: Traffic Calming to Control Speed Source: www.pedbikeimages.org / Dan Burden Source: www.pedbikeimages.org / Dan Burden • Delineate users • Visual traffic calming effects Source: www.pedbikeimages.org / Dan Burden Paving Treatments

11. Applications: Traffic Calming to Control Speed • Delineate the edge • ADA Guidelines • Visual traffic calming effects Source: www.pedbikeimages.org / Dan Burden Source: PCRD / Kumar Paving Treatments

12. Applications: Traffic Calming to Control Volume Source: www.pedbikeimages.org / Dan Burden Source: www.pedbikeimages.org / Dan Burden Diverters, Partial Street Closures • Diagonal diverters create two unconnected streets- intersection • Partial closure for motorized traffic Source: Delaware DOT

13. Applications: Traffic Calming to Control Volume • Partial/ Full closures and diverters are used to retrofit neighborhoods for traffic calming • Full closures- reroute the traffic Full Street Closures Source: PCRD / Kumar

14. Applications: Traffic Calming to Control Volume/Speed Source: www.pedbikeimages.org / Dan Burden Source: www.pedbikeimages.org / Michael Cynecki Source: PCRD / Kumar • Lane reduction is also known as road diets; lane narrowing- visual traffic calming • Gateways- visual traffic calming Gateways, Lane Reduction

15. Applications: Traffic Calming to Control Volume/Speed Source: www.pedbikeimages.org / Dan Burden • Roundabouts are popular techniques • Comprehensive traffic management plan / retrofit Source: www.pedbikeimages.org / Dan Burden Refuge Islands, Roundabouts / Traffic Circles

16. A grassroots effort for narrow street standards is happening Source: FHWA Source: www.pedbikeimages.org / Dan Burden Applications: Traffic Calming • Congress for the New Urbanism • Wider street standards are giving way to narrower streets, particularly in residential areas • More asphalt = More vehicles Traditional Neighborhood / Narrow Streets

17. Applications: Traffic Calming- Streets for Living • Streets designed to be shared by pedestrians, motorists, and the community • Sidewalks, planters, benches are merged into the street • Physical constraints • Speed < 10 miles per hour • Public realm • Higher costs • Emergency vehicles ? Source: Maricopa County Government Woonerf

18. Traffic Calming Impacts- Benefits and Costs • Advocates- • Traffic Calming protects residents, bicyclists, and pedestrians • Multiple and safe use of the street • Critics- • Waste of resources • Shifts the traffic problems from one to another street Source: Todd Litman; Traffic Calming: Benefits, Costs, and Equity Impacts; www.VTPI.org; Calgary health region • Travel Impacts- • Pre and post Traffic Calming travel impacts- motorized / non motorized travel • Assumption- 10-20 % increase in non motorized travel- half of that substitute motorized travel

19. Traffic Calming Impacts- Benefits • Increased Safety • # Significant reduction in accidents • # Payback through lives, injuries, and insurance savings Fatal • Increased non motorized and decreased motorized travel • # Less noise and air pollution; health benefits; parking & gas savings, etc. Source: Todd Litman; Traffic Calming: Benefits, Costs, and Equity Impacts; www.VTPI.org

20. Traffic Calming Impacts- Benefits and Costs • Costs • Project expenses • Liability claims • Vehicle delays • Traffic spill to other roads • Problems for emergency and service vehicles • Driver frustration • Problems for bicyclists and visually impaired • Benefits….. • Increased public realm, interaction and crime prevention- Crime Prevention Through Environmental Design (CPTED) • Defensible Space by Oscar Newman • Increased property values Source: Todd Litman; Traffic Calming: Benefits, Costs, and Equity Impacts; www.VTPI.org

21. Equity is important in Transportation Planning • Horizontal equity is distribution of benefits and costs within groups similar in income, wealth, and ability • Vertical equity is distribution of benefits and costs within groups dissimilar in income, wealth, and ability • A better balancing of different uses of the street- motorists, cyclists, pedestrians, residents • Increased safety for pedestrians, cyclists, residents, and transit users Source: Todd Litman; Traffic Calming: Benefits, Costs, and Equity Impacts; www.VTPI.org Traffic Calming Impacts- Horizontal vs. Vertical Equity

22. Traffic Calming – Planning Process • Public / residents must be involved from the beginning (neighborhood-wide traffic management) • Residents petition for traffic calming (street-wide) • Public Works or Engineering Department propose- traffic calming strategies and devices • Community acceptance is essential • Traffic calming device is put on place • Project evaluation • Traffic calming device is made permanent Safe & Calm Streets

23. Traffic Calming- Sources www.VTPI.org www.ITE.org (Traffic Calming: State of the Practice) www.PBIC.org www.PPS.org www.TrafficCalming.org http://www.fhwa.dot.gov/environment/tcalm/index.htm www.planning.org (Traffic Calming: PAS 456) http://www.io.com/~bumper/ada.htm

24. Thank you!!! ikumar@purdue.edu