The Effects of Data Aggregation on Measuring Arterial Performance

The proliferation of information technology in the transportation field has opened up opportunities for communication and analysis of the performance of transportation facilities. The Highway Capacity Manual relies on rules of thumb and small data samples to generate levels of service to assess performance, but modern detection technology gives us the opportunity to better capture the dynamism of these systems and examine their performance from many perspectives. Travelers, operations staff, and researchers can benefit from measurements that provide information such as travel time, effectiveness of signal coordination, and traffic density. In particular, inductive loop detectors show promise as a tool to collect the data necessary to generate such information. But while their use for this purpose on restricted‐access facilities is well understood, a great many challenges remain in using loop detectors to measure the performance of surface streets.

This thesis proposes 6 methods for estimating arterial travel time. Estimates are compared to simulated data visually, with input/output diagrams; and statistically, with travel times. Methods for estimating travel time are applied to aggregated data and to varying detector densities and evaluated as above. Conclusions are drawn about which method provides the best estimates, what levels of data aggregation can still provide useful information, and what the effects of detector density are on the quality of estimates....

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Creating, Sharing and Updating Regional, State and National Transportation Framework (Centerline) Data Geometry

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Data Science Course - Part 2: Intermediate Scientific Computing for Planners, Engineers, and Scientists with Tammy Lee and Joe Broach

Data Science Course - Part 2: Intermediate Scientific Computing for Planners, Engineers, and Scientists

For the third year, we're hosting our two-part data science course in Portland, OR. You can register for one part or the other– or attend both at a discount: Data Science Course, Part 1: Introduction to Scientific Computing for Planners, Engineers, and Scientists

Did you ever feel you are “drinking from a hose” with the amount of data you are attempting to analyze? Have you been frustrated with the tedious steps in your data processing and analysis process and thinking, “There’s gotta be a better way to do things”? Are you curious what the buzz of data science is about? If any of your answers are yes, then this course is for you.

Classes will all be hands-on sessions with lecture, discussions and labs. Participants can choose to sign up for one or both courses. For more information, download the syllabus (PDF). This course was developed as part of a NITC education project: Introduction to Scientific Computing for Planners, Engineers, and Scientists.

Agenda: Part Two - Intermediate Course

  1. Transforming, visualizing, and modeling data
  2. ...
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An Analytical Derivation of the Capacity at Weaving Sections

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 Past, Present, and Future of Data for Traveler Information

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The video begins at 1:25.

The SFpark Pilot: Using data to make cities better

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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.

Kathryn Doherty-Chapman is a transportation planner focused on helping people access safe and healthy transportation options. She... Read more
Webinar: Modeling Freeway Traffic in a Mixed Environment: Connected and Human-Driven Vehicles - Terry Yang

Webinar: Modeling Freeway Traffic in a Mixed Environment: Connected and Human-Driven Vehicles

 

PRESENTATION ARCHIVE

Miss the webinar or want a look back?

OVERVIEW

Although connected vehicles (CVs) will soon go beyond testbeds, CVs and human-driven vehicles (HVs) will co-exist over a long period. Hence, it is critical to consider the interactions between these two types of vehicles in traffic flow modeling. In this study, we aim to develop a macroscopic model to understand how CVs would impact HVs in the traffic stream. Grounded on the second-order traffic flow model, we study the relationships among flow, density, and speed by two sets of formulations for the groups of CVs and HVs, respectively. A set of friction factors, which indicate CVs' impact to HVs, are introduced to the speed equation for accounting CV speed impacts. Then extended Kalman Filter is employed to update both model parameters and friction factors in real-time. By using CVs trajectory data as measurements, the difference between CV average speed and overall traffic mean speed will be fully accounted. The proposed model will serve as a basis for designing CV-based traffic control function,...

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Piloting Portland's MultiModal Arterial Performance System

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. 

Using Archived ITS Data to Measure the Operational Benefits of a System-Wide Adaptive Ramp Metering System (SWARM)

The video begins at 1:48.

A System-Wide Adaptive Ramp Metering (SWARM) system is being implemented in the Portland metropolitan area and should be operational on all corridors by April 2006. This study entails a before and after evaluation of the operational benefits of the new SWARM system using the existing data, surveillance and communications infrastructure. In particular, the study will quantify system-wide benefits in terms of savings in delay, emissions and fuel consumption and safety improvements on and off the freeway due to the implementation of the ramp metering system. This will aid in the optimal deployment of current SWARM system and will be transferable to other regions as their systems come on line in the future.

Travel Decisions & Their Implications for Urban Transportation: From Campus Transportation to Statewide Modeling

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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...

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