I always take a phone along though it can often be turned off if out for long days. If you do use a phone also look at downloading the RideID app. Again, it is free and allows you to out in the your name and names and number of 2 next of kin along with blood type and any medical issues you may have. I ride on my own a lot and often on the road. I just load the app before setting off, set my phone to airplane mode if I remember, and if the worst does happen at least my name and contacts are known.
Maybe of some use to somebody. Ride safe
