Iron Horse Trail Bridge at Dublin Boulevard

The Iron Horse Regional Trail is a major regional trail for pedestrians and bicyclists through central Alameda and Contra Costa Counties, generally following a former Southern Pacific Railroad right-of-way that was abandoned in 1977. The Iron Horse Regional Trail was first established in 1986 and is maintained by the East Bay Regional Park District. The Trail currently passes through the cities of Livermore, Pleasanton, Dublin, San Ramon, Danville, Alamo, Walnut Creek, Concord, and unincorporated areas of the Counties of Contra Costa and Alameda. The Trail also directly connects to both the Dublin/Pleasanton and Pleasant Hill BART stations. The Iron Horse Regional Trail has several existing bridges over busy roadways to help improve traffic flow on the roadways and pedestrian/bicycle movement along the Trail.

This project is a free-span bridge crossing of Iron Horse Regional Trail over Dublin Boulevard within the City of Dublin. Currently, the Trail runs from northwest to southeast as it approaches Dublin Boulevard, which is a heavily traveled east-west roadway. The existing trail at-grade crossing of Dublin Boulevard is quite skewed. Trail users approaching Dublin Boulevard from the southeast are currently required to turn left and use the sidewalk along the south side of Dublin Boulevard for approximately 200 feet, cross the street at the existing Scarlett Drive signalized intersection, and then turn right and use the sidewalk along the north side of Dublin Boulevard for approximately 100 feet to get back to the Trail.

The primary objective of this project is to provide a safe crossing for Trail users and facilitate improved traffic flow along Dublin Boulevard by providing a grade-separated bridge crossing over Dublin Boulevard for pedestrians and bicyclists.

Construction of the proposed bridge crossing allows Trail users to stay on the Trail and cross over multiple lanes of automobile traffic on the proposed bridge. The overcrossing requires construction of touchdown landings with graduated ramps on the north side of Dublin Boulevard within Don Biddle Park, which is currently under construction, and on the south side of Dublin Boulevard within the existing Iron Horse Trail right-of-way. The proposed main overcrossing structure is approximately 230 feet in length and 20 feet high at the tallest point, where it spans Dublin Boulevard.  The entire project length is approximately 1,200 feet.

MNS is providing complete construction management services for this Class 1 bicycle and pedestrian truss arch bridge over Dublin Boulevard near the intersection of Scarlett Drive. The bridge provides safer and easier access to Iron Horse Trail, access to and from the Dublin-Pleasanton BART station, and connects two existing segments of the Iron Horse Trail. This creates a total separation of bicyclists and pedestrians from motorized vehicles. Construction work consists of miscellaneous clearing and demolition, cast-in-place footing construction, retaining wall installation, walkways, bridge fabrication and erection, Americans with Disabilities (ADA) ramp and steel railing installation, signage, trail lighting installation, paving, and any associated restorations of the site.

The full range of MNS construction management services include performing a pre-bid 95% design constructability review of the construction documents and a bid evaluation; assisting the City’s Project Manage and Designer during the bid solicitation; conducting public works inspection, materials testing, and special inspections; and documenting project closeout.