By the 1950s the Bascule bridge was a significant traffic bottleneck. As part of the nationwide interstate highway system, Congress authorized funding for IH-37 through Corpus Christi. This included money for the construction of a new bridge to be elevated over the channel at a height sufficient to allow the passage of ships without stopping vehicular traffic. In 1959 the current Harbor Bridge was completed, allowing ships with a maximum above-waterline height of 138 feet to pass underneath and use a wider portion of the channel than the previous drawbridge. It also included two narrow pedestrian walkways between the bridge railing and the outermost lane of traffic in each direction. Originally designed with a 50-year lifespan, the bridge will remain in service until its replacement is done in 2023. Thereafter, the bridge is slated for demolition.