Pedestrians

This Technical Summary pertains to Report 2023-18, “Designing and Implementing Maintainable Pedestrian Safety Countermeasures,” published June 2023.

While pedestrian safety countermeasures contribute to reducing vehicle-pedestrian crashes, their impacts on winter maintenance operations are sometimes overlooked during design. There is a need to investigate the best practice guidance and solutions for the design, installation and maintenance of pedestrian safety features for year-round maintenance. To address this, we conducted a search of literature as well as agency interviews to identify and document current best practices for designing and implementing pedestrian safety countermeasures for year-round maintainability. The countermeasures reviewed included curb ramps, crosswalk markings, corner radii, curb extensions, refuge islands, and speed humps and raised crosswalks. The information collected allowed for the development of conclusions and recommendations for these features. The design dimensions and features of pedestrian curb ramps are established by the Americans with Disabilities Act and should have a slope of greater than 1:12 and a maximum cross slope of 1:50. Durable materials can be used for crosswalk markings, and these can be grooved into the pavement to provide protection from abrasion. Bulb-outs should use a 1:2 or 1:3 upstream taper and a 1:3 downstream taper. When used, tight radii of 15 feet or less should be employed. Refuge islands can range from 6 feet or greater in width, 24 feet to 40 feet in length, with a 4-foot or greater walkway width. Finally speed humps and tables should be between 3-4 inches in height, with lengths of 12-14 feet (humps concave in shape) and up to 22 feet (tables).

This report presents a real-time system for pedestrian tracking in sequences of grayscale images acquired by a stationary CCD (charged-coupled devices) camera. The research objective involves integrating this system with a traffic control application, such as a pedestrian control scheme at intersections. The system outputs the spatiotemporal coordinates of each pedestrian during the period the pedestrian remains in the scene. The system processes at three levels: raw images, blobs, and pedestrians. It models blob tracking as a graph optimization problem and pedestrians as rectangular patches with a certain dynamic behavior. Kalman filtering is used to estimate pedestrian parameters. The system was implemented on a Datacube MaxVideo 20 equipped with a Datacube Max860 and on a Pentiumbased PC. The system achieved a peak performance of more than 20 frames per second. Experimental results based on indoor and outdoor scenes demonstrated the system's robustness under many difficult situations such as partial or full occlusions of pedestrians

This report describes a real-time system for tracking pedestrians in sequences of grayscale images acquired by a stationary camera. The system outputs the spatio-temporal coordinates of each pedestrian during the period when the pedestrian is visible. Implemented on a Datacube MaxVideo 20 equipped with a Datacube Max 860, the system achieved a peak performance of over 30 framers per second. Experimental results based on indoor and outdoor scenes have shown that the system is robust under many difficult traffic situations. The system uses the "figure/ground" framework to accomplish the goal of pedestrian detection. The detection phase outputs the tracked blobs (regions), which in turn pass to the final level, the pedestrian level. The pedestrian level deals with pedestrian models and depends on the tracked blobs as the only source of input. By doing this, researchers avoid trying to infer information about pedestrians directly from raw images, a process that is highly sensitive to noise. The pedestrian level makes use of Kalman filtering to predict and estimate pedestrian attributes. The filtered attributes constitute the output of this level, which is the output of the system. This system was designed to be robust to high levels of noise and particularly to deal with difficult situations, such as partial or full occlusions of pedestrians. The report compares vision sensors with other types of possible sensors for the pedestrian control task and evaluates the use of active deformable models as an effective pedestrian tracking module.

This guidebook was developed to help Minnesota transportation agencies evaluate their uncontrolled pedestrian crossings and determine appropriate treatment options. The guidebook recommends when to install marked crosswalks and other enhancements at uncontrolled locations based on a number of factors, including the average daily vehicle count, number of pedestrians, number of lanes, and average vehicle speed. It helps agencies rate a crossing for pedestrian service, and it includes a flow chart and several worksheets to assist in data collection and decision making. When using the guidebook, practitioners are guided through an 11-step evaluation process. Based on the results of the evaluation, users can identify what level of treatment is appropriate for their location, ranging from in-street crossing signs to overhead flashing beacons to traffic calming devices such as curb bump-outs. For each potential treatment option, the guidebook includes information on advantages, disadvantages, recommended locations, and cost. The development of the guidebook was funded by the Minnesota Local Road Research Board.

The data collection worksheets in this spreadsheet pertain to report 2014-21, Uncontrolled Pedestrian Crossing Evaluation Incorporating Highway Capacity Manual Unsignalized Pedestrian Crossing Analysis Methodology.

This Technical Summary pertains to Report 2023-11, “Multi-City Study of an Engineering and Outreach Program to Increase Driver Yielding at Signalized and Unsignalized Crosswalks,” published January 2023.

Pedestrian deaths are at a 30-year high nationally, accounting for 16% of total deaths in 2018 and far exceeding the previous decade of 12%, a trend mirrored in Minnesota. Previous research found an increase in local and citywide yielding at unsignalized crosswalks following an engineering and high-visibility enforcement program in Saint Paul, Minnesota. This study examined a modified engineering-focused (i.e., without enforcement) program expanded to both unsignalized and signalized intersections across the Twin Cities. The six-month study found modest improvements in yielding from baseline to treatment end (48.1% to 65.5% in Saint Paul and 19.8% to 38.8% in Minneapolis) at unsignalized engineering treatment sites but no improvements at generalization sites. No significant improvements in left- or right-turning yielding by drivers in Saint Paul were found at treated signalized intersections, but given that yielding was significantly worse at generalization sites over time, there may be some evidence that treatments mitigated performance declines among Saint Paul drivers during the study period. Yielding improvements at signalized treatment sites were more pronounced for only right-turning drivers in Minneapolis, but generalization sites showed no improvement or even worsened over time. Overall, study results suggested no shift in driving culture in either city, as found with the previous study using police enforcement, but found some evidence of local, site-specific changes in driver yielding behavior at treatment locations.

This Technical Summary pertains to Report 2017-29, “Exploring Walking Tolerance of Transitway Users,” published August 2017.

This Implementation Summary pertains to Report 2017-02, “The Minnesota Bicycle and Pedestrian Counting Initiative: Institutionalizing Bicycle and Pedestrian Monitoring,” and Report 2017-03, “Bicycle and Pedestrian Data Collection Manual,” both published January 2017.