Project Location: Town of Johnson in Lamoille County on VT Route 100C over the right and left branches of the Gihon River. The site is approximately 1.0 mile north of the intersection of VT Route 15 and VT Route 100C in the Town of Johnson.

The Johnson VT 100C Bridges 1 and 2 project will replace the existing superstructures (deck and beams), which have a substandard width, stopping sight distance and structural capacity, with wider superstructures providing improved hydraulic clearance.  The existing Johnson VT 100C Bridges 1 and 2 are 38’ and 54’ long concrete T-beam bridges constructed in 1929 and 1928, respectively.  The current width of the bridges is 21 feet 4 inches.  The bridge superstructure (deck and beams) components are in poor condition, with heavy deterioration in the beams of Bridge 2. 

VTrans evaluated alternatives for replacement of the Johnson VT 100C Bridges 1 and 2  in an engineering study completed in October 2013. The study assessed the proposed design criteria for bridge and roadway alignment, right of way impacts, historical and archaeological resources.   After detailed consideration of several alternative solutions, the recommended complete superstructure replacements, using Accelerated Bridge Construction (ABC) methods, with an offsite detour. 

The new superstuctures will be comprised of prefabricated, bridge elements, which have a relatively short installation period, and    lower construction and maintenance costs. The new 28 ft wide superstructures will be approx. 6.5 ft wider than existings ones, with two 11-foot travel lanes and two 3-foot shoulders.  The new bridges will feature a combination concrete and steel bridge rail that meets historic preservation requirements.

The bridges will be constructed with ABC methods, which will expedite construction and reduce disturbance to the public. The current schedule calls for one road closure at this site for the replacement of both bridge superstructures, prior to Lamoille County Field Days in July. It is anticipated that Route 100c will be closed for 42 days. There is a financial incentive\disincentive clause in the contract to encourage the General Contractor to finish on time.