Texas 20 also includes portions of Texas Avenue in central El Paso, Mesa Street from Downtown to the West Side, and Doniphan Drive on the West Side. Northeast El Paso is connected to West El Paso by Transmountain Road (Loop 375). The city also shares four international bridges and one railbridge with Ciudad Juárez, Mexico. In 2009, El Paso was home to number 52, number 98, and number 100 of the 100 most congested roads in Texas, which are, respectively: North Zaragoza Road between Sun Fire Boulevard and Interstate 10; Lee Trevino Drive between Montana Avenue and Interstate 10; and Interstate 10 between Patriot Freeway and Loop 375. In 2009, 79.8% of El Paso (city) commuters drive to work alone. The 2009 mode share for El Paso (city) commuters are 10.3% for carpooling, 2.4% for transit, 2.5% for walking, and .2% for cycling. In 2016, Walk Score ranked El Paso as the 32nd most walkable of the 50 largest U.S. cities, rating it "car-dependent". The city of El Paso has a slightly lower than average percentage of households without a car. In 2015, 7.4 percent of El Paso households lacked a car, and increased to 8.4 percent in 2016. The national average was 8.7 percent in 2016. El Paso averaged 1.82 cars per household in 2016, compared to a national average of 1.8. The Sun Metro Mass Transit System operates a system of medium- to large-capacity natural gas-powered buses all around the city of El Paso. El Paso County Transit makes trips with small-capacity buses mainly in the eastern El Paso area. In 2011, Sun Metro was named the most outstanding public transit system of the year in all of North America for a mid-size transit system by the American Public Transportation Association. On September 1, 2009, NMDOT Park and Ride began operating commuter bus service to and from Las Cruces, New Mexico. Historically, El Paso and Ciudad Juarez had a shared streetcar system with a peak electrified route mileage of in 1920. The first electrified line across the Rio Grande, which opened on January 11, 1902, was preceded by a network that relied on animal labor. The system quickly spread into residential and industrial areas of El Paso. In 1913, a interurban line was built to Ysleta. At the close of 1943, the holding company El Paso Electric sold its subsidiary, the El Paso Electric Railway Company and its Mexican counterpart, to one of National City Lines' subsidiaries.