D3−3: Widening Bridges to Accommodate Future Construction
The Wisconsin Department of Transportation (WisDOT) has begun to widen some bridges to 56 feet during rehabilitation in order to accommodate four lanes of traffic during future reconstruction. According to the procedure set forth in the Facilities Development Manual the widening decision depends on several factors:
• Projected traffic volumes for the year when the adjoining highway will be reconstructed or rehabilitated (not when the bridge will be overlaid or re−decked);
• The proposed project improvement type for the adjoining highway;
• The hours during which highway reconstruction will cause lane restrictions.
Bridge widening is warranted if:
• Projected Annual Average Daily Traffic (AADT) is between 20,000 and 25,000 with high seasonal peaking characteristics present.
• Projected AADT is less than 20,000 and high summer weekend traffic is present.
• Reconstruction of the adjoining highway is anticipated within 20 years.
REASON(S) FOR ADOPTING:
To allow additional capacity as needed during future rehabilitation activities.
This practice enables four lanes to be maintained during roadway rehabilitation. As lanes are closed traffic is shifted to the shoulder as needed.
MOST APPLICABLE LOCATION(S)/PROJECT(S):
Four lane divided corridors.
STATE(S) WHERE USED:
Peter Amakobe Atepe, Wisconsin DOT Bureau of Traffic Operations
Phone: (608) 261−0138