> Some of the cost could be mitigated with "toll-free" options, such as using a vehicle tracker like EZ-pass and not charging you if you travel less than N miles (to encourage people to live near work), or giving partial refunds if you use your car very little during a month.

Don't know if LA is anything like SF, but here, the poorer you are, the longer your commute is, generally. So this scheme would simply penalize people who already can't afford to live close to work.