There are several auto start/stop features in Travel Logs.

Bluetooth Hands-Free (configured on the vehicle page)
This feature is best for auto starting/stopping all trips when the iPhone is connected the bluetooth device, regardless of the place.

Places (Geo-Fencing)
This feature is best for auto starting/stopping trips when they either depart or arrive at the specified location.

Places (Geo-Fencing) with Bluetooth Condition (configured on the location page)
This feature is best for auto start/stopping trips when they either depart or arrive at the specified location and is also connected to the specified bluetooth device. This feature is designed for locations that you may depart/arrive using various transport options that you don’t always want to track (i.e walking out of the office for lunch).

NFC Tags
This feature is best if you want the auto start/stop feature but you have no access to bluetooth devices, regardless of the place.