Niles Boulevard
Monday – Friday: 7:30 a.m. – 4:00 p.m.
Saturday: 9:00 a.m. – 5:00 p.m. (if needed)

*Due to existing requirements, work taking place directly over or adjacent to BART and Union Pacific Railroad operations will be performed at night and/or on weekends when the trains are not in operation. Regular weekday night hours – when this type of work can take place – are from 1:30 a.m. – 3:00 a.m. Weekend night hours for this type of work are from 1:00 a.m. – 7:00 a.m. Advance notice of night, weekend and/or noisy work activities will be provided to the local community when the work is scheduled.

The majority of project construction is anticipated to take place during regular weekday hours, from 7:30 a.m. to 4:00 p.m. However, there may be instances where weekday construction hours are extended from 7:00 a.m. to 7:00 p.m. in order to expedite or complete ongoing work. Saturday work hours are from 9:00 a.m. – 5:00 p.m. (if needed). Some work may extend into Sunday to complete ongoing work, or to make up for any delays caused by adverse weather.

All construction dates and times are subject to change due to weather and unforeseen conditions, and/or the availability of on-site Union Pacific Railroad flaggers and BART safety monitors.


The Niles Boulevard Bridge spans over the Union Pacific Railroad (UPRR) and BART tracks at the Fremont/Union City border. Following the Loma Prieta earthquake, the bridge was identified by Caltrans for seismic retrofit. Due to high construction costs, long closures of the existing bridge, and limited night time construction hours while BART is not operating, it was subsequently determined the bridge should be replaced rather than retrofitted. Click here to see the project fact sheet.

Viking Construction Company will construct the new bridge. On-site construction activities started in October, 2015 and are anticipated to be complete spring 2017. The new bridge will be constructed immediately south of the existing bridge. Click here to view the October 21 public meeting summary.



The new bridge will provide:

  • Enhanced seismic reliability, preventing the potential for catastrophic failure during a seismic event that could shut down BART and UPRR service for months.
  • Enhanced connectivity for motorists, pedestrians and bicyclists travelling between Union City and Fremont.
  • Pedestrian and Bicycle improvements including landscaped embankments, an improved sidewalk on the south side of the bridge, and bicycle lanes in both directions.

A new cast-in-place, pre-stressed concrete box girder bridge will be built next to the existing bridge, allowing it to remain open during construction. The existing bridge will be demolished once the new bridge is complete, providing for a more cost-effective solution that requires minimal traffic disruption during construction.

The total project cost of the new bridge is approximately $11 million. The construction costs are funded by the federal Highway Bridge Program (HBP), with matching funds coming from state Prop 1B funds.