Title
Department of Transportation recommending the Board adopt and authorize the Chair to sign Resolution 138-2025 to change the existing weight limits on Mount Murphy Road Bridge, bridge number 25C0004. (District 4)
FUNDING: N/A
Body
DISCUSSION / BACKGROUND
On Saturday, September 25, 2021, and January 12, 2025, the Mount Murphy Road Bridge over the South Fork American River in Coloma was closed due to severe structural damage caused by a vehicle colliding with a truss column and the diagonal tension bars on the bridge at an excessive rate of speed, significantly deforming a tension bar. Department of Transportation (Transportation) inspected and repaired the damage from these collision incidents. Transportation posted a sign with reduced weight limit and number of axles after the 2021 bridge damage and repair.
Per County Ordinance 12.20.020, County bridge weight limits are set by resolution of the Board. On December 14, 2021 (Legistar file 21-1876), the Board approved Resolution 188-2021 establishing the current weight limits of Mount Murphy Road Bridge. The new resolution will replace Resolution 188-2021, establishing a new weight posting for the bridge, inclusive of combination truck and trailers up to six (6) axles as requested by the California Department of Transportation (Caltrans). Transportation reduced the posted weight limit after the 2021 repair and did not include combination trucks on the posting. Although a large combination truck would rarely travel this route and is not recommended due to the challenging geometrics, Caltrans’ inspection report recommended the posting be inclusive of combination trucks. Transportation’s proposed new sign includes a reduced weight limit of twenty-four (24) tons for combination trucks.
ALTERNATIVES
The Board could choose not to adopt and authorize the Resolution, allowing the bridge weight limits to remain as posted; however, this could jeopardize continued support of the Caltrans/Federal Highway Administratio...
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