California ? Teen drivers would be barred from driving while using cell phones of any kind – even if fitted with hands-free equipment – under legislation that passed the California Assembly on Monday.

The bill also would prohibit drivers younger than 18 from using text-messaging devices, laptop computers or pagers. If signed by Gov. Arnold Schwarzenegger, the bill would take effect in July.

Violators would be fined $20 for a first offense; repeat offenders could be punished with a $50 fine.

The author of the legislation, state Sen. Joe Simitian, D-Palo Alto , said a new law was necessary because car accidents are the No. 1 cause of death among teenagers. His measure, SB 33, passed the Senate in April and now returns there for a final vote on amendments made by the Assembly.

Starting in July, all drivers, regardless of age, must have their hands free while using a cell phone, under a law Schwarzenegger signed last year.