State Route (SR) 89 Mousehole Pedestrian and Bicycle Improvement Project (Finalist)

The SR 89 Mousehole Pedestrian and Bicycle Improvement Project constructed a 12-foot wide, 120 foot long pedestrian and bicycle tunnel 22 feet under the Union Pacific Railway. Prior to the project, pedestrians or bicyclists wishing to cross under the railroad were required to use the 24-foot wide vehicle tunnel, sharing traffic with vehicular traffic and large trucks. The project also constructed Class I bike/pedestrian paths that connect to paths to the north and south, a transit shelter, and several drainage improvements. Project Benefits: • Improves safety for pedestrians, bicyclists, and motorists. • Provides a bicycle and pedestrian facility along SR 89, connecting Lake Tahoe and Truckee, and Interstate 80. • Reduces congestion and greenhouse gases by promoting non-motorized travel. • Encourages a healthy, active lifestyle by providing recreational facilities. Project Innovation: The railway that travels over the project area is a major east west route and the project construction could not disrupt the railroad operations. Temporary shoofly or railroad realignment alternatives were evaluated but the costs were estimated to be in the $30 million to $50 million range. Sequential Excavation Method techniques were also considered for the replacement of the traffic tunnel. Ultimately, the current project was developed that includes ground freezing, jacking, track monitoring (to check for settlement), and on-site casting of the concrete box. This approach has required significant geotechnical and structural evaluation to develop a construction approach that meets the requirements of Caltrans and UPRR. To our knowledge, this is the first time this construction technique has been approved by Union Pacific Railroad for a tunnel of this size. Project History: The project partners have been planning this project for nearly 20 years. The original vehicle tunnel was constructed in 1928. Between 1997 and 2010, numerous studies were prepared by the Nevada County Transportation Commission, the Town of Truckee, and Caltrans to look at alternatives to improve safety and capacity along this corridor. In 2011 the Town of Truckee took over the final design and construction of the project. The project was completed in 2016. Partnerships: The project is located in the Town of Truckee, Nevada County and is immediately adjacent to the unincorporated portion of Placer County within Caltrans and UPRR Right of Way. With the involvement of all of these agencies, as well as the many stakeholders, the success of this project is dependent on strong partnerships. Funding: Because this project is on the State Highway System, beneath the transcontinental railroad, and on the border of two counties, it serves a significant interregional function. As such, it has received funding from a unique variety of sources, as follows: • Federal (HPP/Federal Earmark, TCSP, TIGER): $4,446,855 • State (STIP/RIP, SHOPP): $7,900,231 • Local (Traffic Impact Fees): $1,800,000