Maintaining Traffic During Construction

Identify the traffic control needs of the project prior to the development of the bridge layouts. Communication between the engineer responsible for traffic control and the design engineer is critical during the preparation of the bridge layouts and during development of the construction sequencing process.
The District’s desired approach (ABC, phased, detour/temporary crossing structures, or temporary bridge structures) must be submitted in writing as part of the Preliminary Bridge Layout Review (PBLR). Although the need to maintain traffic can often by justified, full closure with ABC should generally be considered as the first option. Category 6 funding will be used to cover the additional costs for options other than ABC, only with written approval from the Bridge Management Section Director. It is crucial that these discussions occur early in the planning of a project.
  • Accelerated Bridge Construction
     – Accelerated bridge construction techniques should be considered for every bridge project. Accelerated bridge construction can be a more cost-effective option with less disruption to traffic than lengthy detours or temporary construction.
    • Projects using Accelerated Bridge Construction techniques require early coordination between traffic control engineers and bridge designers to ensure an appropriate balance between cost and acceptable closure times.
  • Phased Construction
     – Replacing an existing bridge with a new bridge may require phased construction. Keeping lanes of the existing bridge open during the first phase of construction of the new bridge can be a cost-effective means of maintaining minimum traffic needs. Use of phased construction must be identified early in plan development and have a written justification showing that it is justified in lieu of ABC.
  • Detour/Temporary Crossing Structures
     – If a project must maintain traffic during a bridge replacement project, detours will only be allowed where an economic justification shows that
    Accelerated Bridge Construction (ABC)
     is more expensive and neither ABC nor phased construction are feasible.
  • Temporary bridge structures are
    not
     a common element in most bridge projects
    . Careful coordination between the bridge designer, traffic control engineer, environmental coordinator, and the bridge project manager should occur early in the process to properly design these structures.
  • Category 6 funding for temporary structures or detours must be approved by the Bridge Management Section
    . Economic justification, including consideration of accelerated bridge construction techniques is required as an alternative to temporary detours.
If the project allows the contractor to provide the temporary bridge for a project, the plans
must
include certain items:
  • The required number and width of traffic lanes and the required design loading.
  • The alignment of the temporary structure.
  • Any special requirements, such as limits on fill, right-of-way, or other environmental restrictions.