On a typical weekday afternoon, the average speed on Interstate 80 through Sacramento drops below 30 miles an hour, according to Caltrans. But help is on the way, in the form of new carpool lanes.

Caltrans is preparing to build 10 miles of new carpool lanes between West El Camino Avenue and Watt Avenue beginning in 2009.

Caltrans estimates the growth in the Sacramento region over the next 30 years will, in some cases, more than double the amount of traffic on existing freeways.

Deputy director for planning, Wayne Lewis, says more carpool lanes will lead to more carpools.