If you go to 2 or more job sites in a single day then the 2nd trip is deductible as a business expense. For example you leave home drive 5 miles to the 1st job then drive 10 miles to the 2nd site. At the end of the day you drive 15 miles home. Only the 10 miles between jobs is deductible. The first trip in the morning, from home and the last trip at night back home are considered commuting and are not deductible*.
If you return home to wait for another job, the mileage for the 2nd (and subsequent) run(s) from your home and back is deductible. That is, you only have one non deductible commute per day.
The cost to get to an "out of town" location, from you home, is deductible and is not commuting. So, in your example, the first 40 mile pick up (and return) is probably deductible. The IRS has no fixed mileage rule for what is out of town. Out of town is outside your metropolitan area.
*To deduct mileage, to the first client and home from the last client (normally commuting trips) the home just needs to be the "Principal Place of Business". It does NOT need to qualify for the Home Office deduction (the 'Regularly and Exclusively' rule does not apply). For an IRS discussion on "Principal Place of Business"see:
https://www.irs.gov/publications/p587#en_US_2018_publink1000226302
