Roadside Design Guide

Roadside Design Guide
Author: American Association of State Highway and Transportation Officials. Task Force for Roadside Safety
Publisher:
Total Pages: 560
Release: 1989
Genre: Roads
ISBN:

Evaluation of the Late Merge Work Zone Traffic Control Strategy

Evaluation of the Late Merge Work Zone Traffic Control Strategy
Author: Andrew G. Beacher
Publisher:
Total Pages: 76
Release: 2004
Genre: Road work zones
ISBN:

Several alternative lane merge strategies have been proposed in recent years to process vehicles through work zone lane closures more safely and efficiently. Among these is the late merge. With the late merge, drivers are instructed to use all lanes to the merge point and then take turns proceeding through the work zone. Its efficiency has been tested on only a limited basis. The purpose of this project was to determine when, if at all, deployment of the late merge was beneficial. The late merge concept was evaluated by comparing it to the traditional merge using computer simulations and field evaluations. Computer simulations included analysis of 2-to-1, 3-to-1, and 3-to-2 lane closure configurations to determine its impact on throughput and the impact of factors such as free flow speed, demand volume, and percentage of heavy vehicles. Field tests were limited to 2-to-1 lane closures, as recommended by state transportation officials, and examined the impact of treatment type on vehicle throughput, percentage of vehicles in the closed lane, and time in queue. Results of the computer simulations showed the late merge produced a statistically significant increase in throughput volume for only the 3-to-1-lane closure configuration and was beneficial across all factors for this type of closure. For the 2-to-1 and 3-to-2 lane closure configurations, the late merge increased throughput when the percentage of heavy vehicles was large. Field tests showed similar trends with regard to throughput. Although throughput increased, the increase was not statistically significant because of the limited number of heavy vehicles at the site. More drivers were in the closed lane, indicating a response to the late merge signs. Time in queue was also reduced, although the reductions were not statistically significant. The authors conclude that the late merge should be considered for 3-to-1 lane closure configurations but not until a sound methodology for deployment has been developed and tested in the field. For the 2-to-1 and 3-to-2 configurations, the late merge should be implemented only when the percentage of heavy vehicles is at least 20 percent.

Human Factors in Transportation

Human Factors in Transportation
Author: Gesa Praetorius, Charlott Sellberg and Riccardo Patriarca
Publisher: AHFE International
Total Pages: 770
Release: 2023-07-19
Genre: Technology & Engineering
ISBN: 1958651710

Proceedings of the 14th International Conference on Applied Human Factors and Ergonomics (AHFE 2023), July 20–24, 2023, San Francisco, USA

Long-term Pavement Marking Practices

Long-term Pavement Marking Practices
Author: James Migletz
Publisher: Transportation Research Board
Total Pages: 165
Release: 2002
Genre: Road markings
ISBN: 0309069246

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 306: Long-Term Pavement Marking Practices documents the current and best practices for managing pavement marking systems, identifies future needs, and addresses driver needs and methods of communicating information to drivers, selection criteria (e.g., reflectivity, pavement service life, wet weather performance), materials (e.g., color, durability, cost), specifications, construction practices, inventory management systems, and more.