While many consider Antioch the gateway to the Delta, the prevailing features of the area have attracted an influx of new arrivals by continually providing an abundance of charm and opportunity. Population has risen throughout Contra Costa County, although growth has been particularly robust in the eastern portion of the county, which includes the city of Antioch. The residential development continues at a healthy rate; embracing well-planned, controlled growth, to retain the area's character and appeal that will continue to attract residents in the future. Highway 4 is the major east-west highway. Contra Costa County, as well as the City of Antioch, is responding to the explosive population growth by taking sufficient measures to alleviate potential congestion problems. The measures include the the expansion of BART and the widening of Highway-4, which will expand the existing four lanes into eight with projected completion by 2010.