Research by Ellen Oettinger White – Unclear territory: Clear zones, roadside trees, and collaboration in state highway agencies

May 3, 2023

Abstract

The American Association of State Highway and Transportation Officials (AASHTO) issues guidance for highway agencies to maintain clear zones adjacent to the roadbed, free of trees, to reduce the severity of run-off-the-road crashes. Some departments of transportation (DOTs) are clearing trees beyond the standard clear zone for road safety, creating friction between units of different disciplines.

Following an analysis of roadside tree literature, I use semi-structured interviews with agency staff to illuminate how perceptions of trees—either as safety hazards or as beneficial environmental assets—are considered by practitioners at state highway agencies.

Results indicate that engineering leadership understands roadside tree management as a nuanced issue. The benefits of trees are understood by most staff though are rarely a sufficient counterweight for perceived safety issues. Maintenance staff are motivated more by budgets or contracts than by research or federal guidance. An interdisciplinary staff structure, robust communication practices, and stronger environmental policy can improve DOT collaboration.

Ellen Oettinger White, Unclear territory: Clear zones, roadside trees, and collaboration in state highway agencies, Transportation Research Part D: Transport and Environment, Volume 118,
2023, 103650, ISSN 1361-9209, https://doi.org/10.1016/j.trd.2023.103650.

Recent Posts

NJSPL – New Jersey Employment Concerns Revisited

As 2024 began with yet another surprisingly strong jobs report for the U.S. (353,000 jobs added in January and the unemployment rate steady at 3.7%), and with a full year’s worth of 2023 state-level employment data now available, it’s worth briefly revisiting some of...

New Research: The Traffic Calming Effect of Delineated Bicycle Lanes

Abstract We analyze the effect of a bicycle lane on traffic speeds. Computer vision techniques are used to detect and classify the speed and trajectory of over 9,000 motor-vehicles at an intersection that was part of a pilot demonstration in which a bicycle lane was...

Upcoming Events

Event Series CAREERS

Career Virtual Drop-ins

Virtual

Bloustein Career Development Specialists Cheryl Egan and Andrea Garrido will be in a Zoom Room on Monday's beginning January 22, 2024 (excluding holidays and spring break) to answer questions, provide […]