Numerous revisions were made at 21st Street and Boulder Drive as part of the 21st Street bridge/Riverside Drive interchange project. For starters, a new south approach for northbound traffic only was built to connect Riverside Drive to 21st Street, thus creating a four-way intersection at 21st Street and Boulder Drive. The approach has two through lanes and left- and (express) right-turn lanes. The east approach was repaved with four lanes and a concrete median, plus a westbound express right-turn lane, while the west approach was reconfigured to allow the bridge to be utilized as the main lane with four lanes and an eastbound left-turn lane at Boulder Drive. The former 21st Street alignment to the west now is a one-lane, one-way street that connects to northbound Riverside Drive only. The former eastbound lane now is a dirt and grass area, and the traffic signal at 21st Street and Riverside Drive has been eliminated. Traffic wanting to go southbound on Riverside Drive now uses a ramp off the 21st Street bridge (shown in the background). Eastbound traffic on the 21st Street bridge also can access northbound Riverside Drive via a ramp (did not exist before the project), but no access is allowed to southbound Riverside Drive from this ramp. There are occasions where eastbound motorists make a U-Turn on the bridge to access the westbound ramp to go south on Riverside Drive, but this maneuver is not recommended. The project, which was funded by the 1980 sales tax, also included widening and rebuilding Riverside Drive from just north of Denver Avenue to 24th Street. The overall project began in July 1982 with the demolition of the railroad bridge west of the river and construction of a new span, which was completed in June 1983. However, the railroad bridge remained closed until the river bridge was closed in August 1983, at which time it opened. Work then began on the river bridge, followed by the intersection project in May 1984, with both projects being completed in September 1985. The street then was open in its entirety for the first time in more than three years. Photo taken October 1985.
