Analysis of Complex Weaves in Managed Lanes

With the challenges of increasing traffic congestion, the concept of managed lanes (MLs) has been gaining popularity recently as a means to effectively improve traffic mobility. MLs are usually designed to be left-lane concurrent with an at-grade access/exit. Such a design forms weaving segments since it requires vehicles to change multiple general purpose lanes (GPLs) to enter or exit the ML. The weaving segments could have a negative impact on traffic safety in the GPLs. This study provides a comprehensive investigation of the safety impact of different lengths for each lane change maneuver on GPL weaving segments close to the ingress and egress of MLs through two simulation approaches: VISSIM microsimulation and driving simulator. The two simulation studies are developed based on traffic data collected from freeway I-95 in Miami, Florida. The results from the two simulation studies support each other. Based on the two simulation studies, it is recommended that 1,000 feet be used as the optimal length for per lane change at the GPLs weaving segments with MLs. The safety impact of traffic volume, variable speed limit control strategies, and drivers’ gender and age characteristics are also explored. This study can provide valuable insight for evaluating the traffic performance of freeway weaving segments with the presence of concurrent GPLs and MLs in a highway safety context. It also provides guidelines for future conversion of freeways to include MLs.

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Technological and Human Factor Considerations for Priced Managed Lane Traveler Information Systems

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118758680 ◽

2018 ◽

Vol 2672 (14) ◽

pp. 10-19

Author(s):

Nicholas S. Wood ◽

Chris Simek ◽

Susan T. Chrysler ◽

Jeff Kaufman ◽

Shawn Turner ◽

...

Keyword(s):

Information Systems ◽

Third Party ◽

Managed Lanes ◽

Trip Planning ◽

Traveler Information ◽

Traffic Incidents ◽

Traveler Information Systems ◽

National Review ◽

Online Availability ◽

Lane Closures

Travelers have many unique informational requirements to be able to navigate priced managed lanes. These demands often relate to specific managed lane features (e.g., access points, toll price) in addition to information about major traffic incidents and lane closures. Accommodating these needs with traditional roadway signage is a particular challenge given concerns about overloading and distracting drivers. This paper summarizes an investigation into traveler information systems for managed lanes, by considering a national review of current agency practices, a traveler survey, and an assessment for integrating advancing technologies. The national review found that many agencies vary considerably in pricing structure, number, and placement of priced destination points, and online availability of real-time toll information. A travel survey of 866 Texas-based respondents indicated that drivers prioritize information about traffic incidents and lane closures over toll price data (94% and 88% versus 41%, respectively). A higher share of respondents wanted to see travel time and incident alerts on in-vehicle devices, compared with a more statistically significant desire for destination and toll rate information on roadway signs. Most respondents use smartphone applications and mapping websites for pre-trip planning purposes (79% and 65%, respectively) compared with TV and radio reports (13%). Comparatively, prior research published 5 years earlier found that radio was a highly influential media in influencing behavior. This paper suggests a pathway for agencies to adopt a flexible approach for sharing essential data with third-party entities, based on the general transit-feed specification used for transit.

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