Employee business expenses such as mileage are no longer deductible for federal taxes under the new laws.
"You can no longer claim a deduction for unreimbursed employee expenses unless you fall into one of the following categories of employment, or have certain qualified educator expenses.
Armed Forces reservists.
Qualified performing artists.
Fee-basis state or local government officials.
Employees with impairment-related work expenses." https://www.irs.gov/publications/p529