Synthesis of Information Related to Highway Practices. Topic 49-06. Design and Maintenance Practices for Urban Freeway Roadside Vegetation

Designing and maintaining roadside vegetation in highly developed urban settings is increasingly challenging for state transportation agencies (DOTs). In many cases, park-like and ornamental plantings installed on urban roadsides when the freeway was originally constructed have proven unsustainable for DOTs. The inability to adequately access and maintain these areas has resulted in failure of planted vegetation, loss of investment, and public criticism of state transportations agencies. Factors contributing to the challenges of designing and maintaining urban freeway roadsides include: (1) Constant high traffic volumes create safety risks for maintenance workers, difficult site access, and extensive traffic control requirements. (2) Ongoing expensive investment in added labor, equipment, and materials, particularly where permanent irrigation and perpetual mowing is required. (3) Illegal camping by transient populations. (4) Noxious and invasive vegetation problems. The objective of this synthesis is to document practices by DOTs to address problems related to urban freeway roadsides. The synthesis will focus on design and maintenance of vegetation along high visibility urban freeways with limited pedestrian access, such as wider medians, interchanges, roundabouts, and overpasses. Information to be documented includes, but is not limited to, the following: (1) Goals for vegetation management (e.g., safety, aesthetics, tourism, sustainability); (2) Roadside design and installation specifications; (3) Roadside integrated vegetation management plans for urban roadsides; (4) Qualification, training, and certification of designers, construction inspectors, and maintenance staff relative to the vegetation aspects of an urban freeway roadside project; (5) Strategies and policies related to appropriate plant selection and placement; (6) Other challenges encountered by DOTs with vegetation management along urban freeway roadsides; (7) Maintenance agreements between DOTs and local entities; (8) Effective vegetation deterrents to illegal camping and other unauthorized uses; (9) Work zone safety (e.g., access, personal safety, biohazards, wildlife); and (10) Lessons learned. Information will be gathered through literature review, survey of all state DOT agencies, and follow up interviews with a least four agencies for case examples. The survey will be directed to state maintenance engineers. Surveys require an 80% response rate. The synthesis will identify gaps in knowledge and research that could address those gaps. 


  • English


  • Status: Active
  • Funding: $45000
  • Contract Numbers:

    Project 20-05, Topic 49-06

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Gause, Jo

  • Performing Organizations:

    Texas A&M Transportation Institute, College Station

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Storey, Beverly

  • Start Date: 20171116
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 41610

Subject/Index Terms

Filing Info

  • Accession Number: 01634825
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-05, Topic 49-06
  • Files: TRB, RiP
  • Created Date: May 17 2017 1:00AM