Portland State University

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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SFpark was a federally-funded pilot program of a new approach to managing parking in San Francisco. It utilized real time data to identify parking availability, and demand-responsive parking pricing to help make parking easier to find. Parking management is an invaluable transportation demand management tool and the SFpark pilot demonstrated how data can help cities make smarter decisions. Come hear about the pilot evaluation results from a former SFpark staffer and PSU alum.

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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. 

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Where: Room 204 of the Distance Learning Center Wing of the Urban Center at PSU

The ability to forecast future transportation patterns under a particular land-use scenario or urban form is key to making informed decisions at the local and regional levels.

Although several researchers have explored the links between the built environment, socio-demographics and travel behavior, a consensus is not reached.

This talk highlights two recent projects. The first project focuses on individuals’ attitudes towards transportation, neighborhood characteristics and their effects on campus commuters’ transit use, and addresses the question whether attitudes, the built environment or a combination of both explains the resulting transit use better.

The second part presents the Regional Land Use Allocation Decision Analysis Tool developed for The Ohio Department of Transportation, which enables decision makers to quantify the impacts of population and employment distribution in terms of the resulting VMT (Vehicle Miles Traveled). This tool forecasts the impacts of future land-use policies in Ohio, based on alternative assumptions of highway and mass transit corridor development, zoning and environmental constraints, regional growth or decline...