SAN DIEGO -- Beginning Friday, the California Highway Patrol will greatly expand its use of radar to catch speeders on San Diego freeways.

CHP officers have been using radar guns to clock vehicle speeds on stretches of Interstates 5 and 15 for years, but now they will start using them on all other local freeways, officials said Friday.

"With the addition of radar enforcement to all local freeways, our officers have one more tool to utilize in their efforts to reduce collisions and increase safety for motorists," said Capt. John Bailey, commander of the San Diego-area CHP office.

Speeding is the No. 1 cause of traffic accidents, Bailey said.