Route 237 begins at a junction of Grant Road with El Camino Real (SR 82) in Mountain View, as a four lane divided highway. Most traffic comes from California State Route 85. Westbound traffic can connect to Route 85 southbound, but the eastbound traffic connection to Route 85 northbound is labeled as an exit for U.S. 101. Route 237 intersects with Highway 101 at the southern corner of Moffett Field. After this intersection, a carpool lane is added, for a total of three lanes in either direction. It remains like this until the east end of the freeway at Interstate 880, where most eastbound traffic is directed to northbound I-880. The route then becomes a city street (an arterial road), Calaveras Boulevard, in Milpitas, terminating at Interstate 680.