Enjoying the landscapes while you relax with a train’s gentle rhythm is a good way of travelling if you have bladder issues, because there are bathrooms onboard. When you book your tickets, ask how the station is equipped when it comes to bathrooms and also ask for a seat near a bathroom.
If you are the driver, you are in control and can decide when to take breaks. So all is fine, as long as you don’t get too carried away by your favourite highway soundtrack and forget to stick to your bathroom schedule. If you are the passenger, prepare the driver in advance about your need for breaks. If you are with someone who doesn’t know about your bladder issues, it might be good to tell them that you need to go when you need to go (not necessarily just when you stop for petrol). Just say you need to use the bathroom at fixed times – no more explanation is required. Use the WheelMate app to locate the nearest bathrooms on your trip.
Some buses have a tiny bathroom onboard (usually involving stairs). If this is inconvenient for you, ask the bus company in advance when the planned breaks are, so you can see if you can make it fit with your own catheterisation schedule. You can also consider taking a catheter and bag solution, enabling you to catheterise on the bus. Don't forget to take a blanket as well for privacy.