The recent freeway accident shows what a catarosphic event can happen when a gasoline tank truck explodes. This could happen in Palo Alto.
A car running a red light at Middlefield and Charleston could crash into a tank truck traveling across town on Charleston Rd.. This could happen at Alma also.
There are obviously for many reasons for a crash/fire.
The police don't do traffic, truck policing, enforcement on Charleston. They don't have time.