Do you and your wife both have iPhones? If so, you already have a tracking app. "Find my Friends" is preloaded on iPhones. It's not the best, but it does the job. I use it a lot when riding my motorcycle.
One thing to consider, depending on where you cruise
, is that you of course need phone service
for any tracking app to work. Without that, you should check out a Spot or Delorme Inreach (has the ability to send and received texts, and also you can pay for the plan monthly).
The ability for my wife to see my on a map - and see that I am moving - really helps ease her fears.