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File #: 2019-1365   
Type: Consent Calendar Item Status: Passed
File created: 8/27/2019 In control: Transportation and Public Works
On agenda: 10/8/2019 Final action: 10/8/2019
Title: Vehicle Length Restriction on Portion of Lambert Bridge Road
Department or Agency Name(s): Transportation and Public Works
Attachments: 1. Summary Report, 2. Resolution, 3. Location Map

To: Board of Supervisors

Department or Agency Name(s): Transportation and Public Works

Staff Name and Phone Number: Johannes J. Hoevertsz 707-565-2231

Vote Requirement: Majority

Supervisorial District(s): Fourth




Vehicle Length Restriction on Portion of Lambert Bridge Road



Recommended Action:

Recommended action

A)                     Determine that, in consideration of public safety, Lambert Bridge Road between Postmiles 10.34 and 10.54 cannot sustain the operation of trailers or semi-trailers with kingpin to rear-most axle lengths exceeding 38 feet.

B)                     Adopt a Resolution prohibiting vehicles with trailers or semi-trailers with kingpin to rear axle lengths exceeding thirty-eight feet (38’) on Lambert Bridge Road between Postmiles 10.34 and 10.54

C)                     Directing the Director of Transportation and Public Works to install associated signage.

(Fourth District)



Executive Summary:

The Department of Transportation and Public Works (TPW) is in the process of repealing Ordinance 2652, which regulates the weight of vehicles crossing the Lambert Bridge.  Upon execution of the ordinance repealing this weight limitation, the department expects that large trucks usage of the bridge will increase, as will potential closures of and damage to the bridge resulting from these larger vehicles striking the bridge. This resolution would create length limitations on Lambert Bridge, allowing for installation of all regulatory signage and enforcement.



Lambert Bridge Road carries an average daily traffic (ADT) volume of approximately 1,500 vehicles per day, and services the transportation needs of the immediate unincorporated area providing a direct connection west to West Dry Creek Road and east to Dry Creek Road.  Lambert Bridge, installed in 1915, is a one-lane bridge that spans Dry Creek with tight-angle roadway turns at the approaches, requiring negotiation of short-radius turns in order to enter and exit the bridge.

Historically, the Lambert Bridge has been struck numerous times by vehicles of an inappropriate length attempting to navigate the approach curve, causing damage to the railing and truss.  This is due to the narrow width of the bridge, two sharp curves at and east of the eastern bridge approach, and constrained overhead clearance. An increase in the number and size of tractor-trailer vehicles using the bridge is expected once the weight limitation is removed. This traffic increase would increase the potential that over-length vehicles will damage or block the bridge, as has happened at other similar one-lane County bridges. Not only is property damage risked, but also the safety of drivers and the reliability of the bridge as a viable means for traversing over Dry Creek. The Department has also determined that advisory warning signs alone are relatively ineffective in limiting inappropriate length vehicle traffic. All these factors make it imperative that vehicles of an inappropriate length should be prohibited from traversing Lambert Bridge.

Section 35401(e) of the California Vehicle Code allows local officials, in consideration of public safety, to limit the length of vehicles with trailers or semi-trailers that are allowed to use a given roadway. Pursuant to Section 35401(e), a county considering imposition of vehicle length restrictions on a given roadway shall consider all of the following:

(1) A comparison of the operating characteristics of the vehicles to be limited as compared to operating characteristics of other vehicles regulated by this code.

(2) Actual traffic volume.

(3) Frequency of accidents.

(4) Any other relevant data.

Staff has conducted an engineering and traffic evaluation of Lambert Bridge Road and is recommending that length restrictions be established limiting vehicles with trailers or semi-trailers to a maximum length of thirty-eight feet (38’) kingpin to rearmost axle. Once imposed, violations of vehicle length restrictions may result in citations or fines to the drivers in addition to recovering specific costs associated with extricating the vehicle.

Should length restrictions be imposed on Lambert Bridge, large vehicles still could access areas otherwise served by the bridge via alternative routes on West Dry Creek Road #99017 and Dry Creek Road #9901.

Accordingly, TPW is requesting that the Board adopt a resolution creating vehicle length restrictions.

The estimated cost of labor and materials to implement the resolution is $3,500 and appropriations are available within the 2019/2020 Road Maintenance Budget. If approved, staff will begin work to install vehicle length restriction signage and markings to coincide with the effective date of the related ordinance to repeal existing weight restrictions on Lambert Bridge.


Prior Board Actions:

08/05/1980: Adoption of Ordinance 2652 providing for and regulating the weight upon and over the bridge over Dry Creek on Lambert Bridge Road.


Fiscal Summary


FY 19-20 Adopted

FY20-21 Projected

FY 21-22 Projected

Budgeted Expenses




Additional Appropriation Requested




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Narrative Explanation of Fiscal Impacts:

Appropriations are available within the FY 2019-20 adopted Road Maintenance budget for the installation of signs, and will be funded with Road maintenance operating revenues comprised largely of state gas tax. There is no impact to General Funds for these costs.


Staffing Impacts:




Position Title (Payroll Classification)

Monthly Salary Range (A-I Step)

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Narrative Explanation of Staffing Impacts (If Required):




Location Map, Resolution


Related Items “On File” with the Clerk of the Board:

Ordinance 2652