Portland State University

This fall, the Friday transportation seminar series at Portland State University has focused on data collection and how information is used to make transportation investments. The Oct. 26 seminar, with the University of Minnesota’s Greg Lindsey, covered tracking and modeling travel behavior.

Engineers and planners alike have relied on traffic counts for their traffic models, but data behind bike and pedestrian travel has been fuzzy. Now, researchers such as Lindsey are offering new methods for conducting bike and pedestrian counts on trails and multiuse paths.

With little guidance from the Federal Highway Administration, Lindsey said, most of the efforts in creating best practices have bubbled up from communities like the Twin Cities, chosen as Nonmotorized Transportation Pilot Cities. Lindsey and his researchers monitored six trails in Minneapolis, using inductive loops and infrared beams.

To address calibration problems and offer validity to their field numbers, Lindsey also sent students into the field to verify counts. The technology allowed for finer-grained detail, especially over a 24-hour period. OTREC Director Jennifer Dill noted, “Too much in the past we’ve lumped “bike and peds” together and your work and analysis is demonstrating that they truly are different modes, with different behaviors.”

Lindsey stressed the importance of conducting this type of research, and measuring our “bicycle miles traveled” and “pedestrian miles traveled” in...

PSU Special Transportation Seminar:

An analytical derivation of the capacity at weaving sections consistent with empirical observations and micro-simulated results

Where: ITS Lab, Room 315, PSU Engineering Building

Summary: Weaving sections are discontinuities of the highway network formed when merge segments are closely followed by diverge segments. Because of their geometrical configuration, weaving areas generate numerous lane changes. Those lane changes lead to a reduction of the capacity and affect therefore the operation of weaving sections. 

This contribution aims at investigating empirically the lane changing behavior at a weaving section located in Grenoble (France). The data have been collected at a microscopic level, describing the position of every vehicle at every time step (trajectories of each individual vehicle). The data have been measured with a high-resolution camera mounted underneath a helicopter. 

From the empirical results, we develop an analytical formulation of the capacity of weaving sections. We consider a theoretical weaving section as the superposition of two merges and two diverges. We assume moreover that the accelerations and slowdowns of weaving vehicles create voids in the traffic stream that reduce the total capacity. The analytical estimation of the capacity is compared with field macroscopic data measured in Grenoble and micro-simulated results.

The specification of the needed data sample to...

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The video begins at 3:38.

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Summary: Shaun will present on the recently completed pilot demonstration of multimodal arterial performance measures for the Portland metro region, as part of the larger regional concept of operations. Treatments include a permanent bike count station on the Springwater Trail, permanent truck classification stations, Bluetooth travel time stations, as well as leveraging existing transit and signal controller data to paint a picture of the collective modal transportation system.

Bio: Shaun Quayle is a transportation engineer with Kittelson and Associates, Inc. (www.kittelson.com). His focus areas of practice are in the operations, planning and design of arterial traffic signal systems, performance management systems, and complex traffic analysis and simulation.