Everyone has made good points. I started travelling for work 12 years ago. And as everyone has said, your friends may think its all glamorous, but its really not. Yes, you may get to go to some cool places, but you rarely have time to see the sights. I mainly fly, so that can be annoying but you have to learn to roll with the punches and not get worked up over delays, etc.
You mentioned that you would be driving (no mention of flying). If that's the case I would also have questions like do you get a company car, can you use a rental, or are you expected to use your personal vehicle and get mileage? In my mind mileage won't be enough to support the wear & tear on your vehicle and cover gas. If I use my personal vehicle for a nearby engagement, I can expense mileage, or expense fuel, but not both. Something to consider. Also, if doing a lot of driving that can be tiring as well. Some folks I know would rather drive, but for me I'd just as soon fly. If I have the choice of driving 6 hours vs. a flight that overall consumes the same amount of time (flight time, plus airport time, etc.) I'll choose flying every time.
Also be wary of "you'll only be gone three days a week". I was initially told something similar, like you'll travel to a gig Monday mornings and come home Friday afternoon. That didn't last very long when things may demand you're there first thing Monday morning or something like that. Even if driving, do you want to get up and drive 3 or 4 hours to be somewhere at 8, or drive out Sunday night, so you can not be rushed and fresh for Monday morning? Those things creep in.
Also consider you home life as everyone has said but don't forget your personal free time as well. Before my current job, I was extremely active in the shooting sports, actual team sports and off roading. That went by the wayside quick as I just didn't have the time to devote to relationship, my personal fun time, and just normal stuff around the house/yard, etc. After getting home on a Friday, getting up at 4:30 AM the next day to drive several hours to go to some rifle match was just not very appealing at times. Or, Yeah, I'd love to take the jeep on that weekend trip, but I have to head out Sunday night to be someplace Monday morning. My kids were almost grown when I started, so that was not a huge deal, and my better half and I are both very independent working people so there was not this need for constant mutual in person support or dependence.
Something else to think about is if you will be what we call, virtually connected, i.e. you work from home and don't report to a specific office, its much more demanding that working in the office environment. You have to be a self starter and not in need of that office/workplace social fix that many people seem to need. And you will find yourself answering emails, tinkering with some report or some such after normal hours. It's just the nature of things. The last time I had a face to face with my manager was a year and a half ago. In fact at that same time, it was the first time a had met some of the other members of my team face to face. It's different and you're not always in tune with what is "going on" with the company.
All that said, Unless you are working with a specific set of customers/clients, every day is different, every place can be new, and you'll meet a ton of people (some interesting and some not so much). I've built some very good relationships with repeat customers over the years, and have on occasion had time to see and do some really cool things on the road. I work out my home, so when I'm not on the road, I'm home, which is good. I'ts not for everyone, but I would not trade it for the world. I hate the thought of going into an office and sitting in a cube every day.
Good luck!