Commuting expenses between your home and main workplace are never deductible, even if your workplace is far away or you conduct business or haul work supplies during your commute. (A few states allow you to deduct certain commuter related expenses, but that has to be done on your state return.)

However, if you travel to and from a temporary work location (where your assignment is expected to last no more than 1 year) outside your metropolitan area, you can claim commuting expenses. You can also claim commuting expenses to and from a temporary work site, regardless of location, as long as your main workplace is elsewhere.

You're also allowed to deduct commuting expenses between multiple job sites during the same day. For example, if you go directly from your day job to your evening job, you can deduct the commute between those 2 job sites. But if you first go home and then leave to go to your second job, that can't be deducted.

Qualifying travel expenses for employees are reported on Form 2106 and are subject to the 2% rule.

For more information about the 2% rule, read this FAQ: https://ttlc.intuit.com/replies/4800344