"The method used to deduct expenses depends on whether you are
self-employed or are employed by someone else. Self-employed individuals
generally take their travel expenses as a deduction against
self-employment income, while those who are employed by others take
their unreimbursed employee expenses as an itemized deduction on
Schedule A, limited to amounts above 2% of their adjusted gross income
(AGI)."
See this FAQ on whether you can deduct vehicle expenses:
https://ttlc.intuit.com/replies/3301737