You can deduct the ordinary and necessary expenses of traveling away from home if the primary purpose of the trip is to collect rental income or to manage, conserve, or maintain your rental property. You must properly allocate your expenses between rental and nonrental activities. You can’t deduct the cost of traveling away from home if the primary purpose of the trip is to improve the property. The cost of improvements is recovered by taking depreciation. To deduct travel expenses, you must keep records that follow the rules in chapter 5 of Pub. 463.
See https://www.irs.gov/publications/p527#en_US_2018_publink1000218997 and
https://www.irs.gov/publications/p463#en_US_2018_publink100033810
