Join us for the first PSU Friday Transportation Seminar of 2014. The event is free and all are welcome!
Pedestrian Crossings, Bicycling and Transit Stop Removal:
3 Transportation Research Board (TRB) annual meeting student presentations
Friday, January 10, 2014 12:00 pm - 1:00 pm
Where: Room 204 of the Distance Learning Center Wing of the Urban Center at PSU
Speakers: Nick Foster, Christopher Muhs and Zef Wagner, Portland State University
Evaluating Driver and Pedestrian Behaviors at Enhanced Multilane Midblock Pedestrian Crossings: Case Study in Portland, Oregon This study examines driver and pedestrian behaviors at two enhanced midblock pedestrian crossings in Portland, Oregon. One crossing is on a five-lane arterial with a posted speed of 35/45 miles-per-hour (MPH) and features six rectangular rapid flash beacon (RRFB) assemblies and a narrow median refuge. The other crossing is on a suburban arterial with four travel lanes and a two-way left-turn lane. The crossing is enhanced with four RRFB assemblies and a median island with a “Z” crossing, or Danish offset, designed to encourage pedestrians to face oncoming traffic before completing the second stage of their crossing. Approximately 62 hours of video have been collected at the two locations. A total of 351 pedestrian crossings are analyzed for driver compliance (yielding) rates, pedestrian activation rates, pedestrian delay, and conflict avoidance maneuvers. The suburban arterial crossing is also evaluated to determine its effectiveness at diverting pedestrians to cross at it instead of away from a crosswalk, as well as pedestrian compliance with the Z-crossing. This study finds that average driver yield rates at both sites are just over 90% when the RRFB is activated, which is consistent with previous studies. RRFB actuation rates range from 83% to over 90%. The results also show that approximately 52% of all crossings at the marked crosswalk at the second location are from diverted pedestrians and that the enhanced crossing captures about 82% of all crossings near the crosswalk. Finally, approximately 52%, of the pedestrians using the crosswalk follow the Z-crossing pattern through the median.
Bicycling Is Different: Built Environment Relationships to Nonwork Travel There is growing investment in infrastructure to support non-motorized travel modes in the United States, in particular for bicycling. However, there remains a dearth of knowledge on the relationships between built environments and bicycling for non-work transportation. This issue is exacerbated by researchers and practitioners continuing to combine walking and bicycling into the category “non-motorized modes,” despite the two having many differences. This paper addresses these shortcomings through a segmented analysis of mode choice and mode share for walking, bicycling, and automobile travel. The data used are from a 2011 establishment intercept survey in the Portland, Oregon region and are destination-based. Results show pronounced differences in the empirical relationships between walking and bicycling and the built environment, when controlling for aspects of the individual, site, and trip. Models for mode choice and mode share indicate that the built environment attributes that influence automobile and walk travel are similar; yet, their influence is in the opposite direction. Empirical relationships with the built environment are altogether different for bicycling trips. Socio-demographic variable results are consistent with much of the non-work mode choice literature, but trip distance is not. Trip distance has the expected relationship with walking, but does not have a significant relationship with bicycling. The findings on the built environment relationships with travel modes support a move away from combining walking and bicycling together as non-motorized transportation for analysis and planning. They also lend insight into additional considerations for future work in non-work transportation research and policy.
Benefit-Cost Evaluation Method for Transit Stop Removal The introduction of wider stop spacing through the removal or consolidation of existing stops is one method transit agencies can use to reduce travel time and reliability on many transit lines. A great deal of research has been done to provide tools for determining optimal stop spacing, but tools are still needed to help service planners determine the optimal stops to remove. Stop-level bus performance data provide the information needed to develop a method for assessing the total benefits and costs to riders of removing individual stops. This tool compares the benefit to through-riders in terms of travel time savings with the additional access cost to riders using the stop. The tool was applied to a bus route in Portland, Oregon, using stop-level ridership data from TriMet, the regional transit agency. The case study identifies three stops with very high benefit-cost ratios and discusses the effects of removing those stops. A sensitivity analysis is performed to show the effect of changing the value of time factor or the assumed time savings from each stop removal. Further research needs are identified and tradeoffs are discussed regarding the use of this tool. Overall, the assessment tool provides a relatively simple way for transit service planners to identify ideal stops for removal or consolidation.
Watch a video of the seminar: Stream
Download video: Download (m4v)
Download audio: Download (mp3)
View slides: Foster Presentation (PDF)
View slides: Muhs Presentation (PDF)
View slides: Wagner Presentation (PDF)