Here are some easy solutions:
Have the State Patrol (in Washington and Oregon) create an entry-level position, with troopers on the highways, freeways and state routes armed with photo guns, take photo of phone offenders, talking or texting, and fine them like a drunk driver is fined. If someone wants to dispute it they can sign a waiver of the driver's cellphone usage to prove that they weren't texting or talking on the phone. It should also be reported to the insurance companies as a major infraction.
Have all commercial trucks pay for using Interstate 5 between 6 and 9 a.m. southbound and 3 and 6 p.m. northbound.
Find a crossing area west of the I-5 with state routes connecting it.
Have a "heavy traffic" driver pass. The drivers would have to pass a heavy traffic drive course to get the chip that would be installed on their vehicle and would allow them to use the I-5 bridge between 6 and 9 a.m. southbound and 3 and 6 p.m. northbound. If they don't have the pass they would have to find another way to get over the bridge.
These solutions will help the traffic flow and raise money for interstate travel.