Rare is the occupation that doesn't take you on the road at least once in a while. I actually don't travel very often (three times per year or less) however one multiple day road trip can seriously derail your training and your diet if you aren't pro-active.
For example last year while in Detroit at the NCAA Final Four, I didn't break a sweat the entire five days. I also became very familiar with the Wendy's a block from our hotel, along with the hospitality food available at the various cocktail functions. Needless to say, this was NOT the way to handle a road trip.
I was out of town for work last weekend and tried to be much more pro-active with regards to my meals. I brought several cans of tuna (along with my can opener), a few protein shakes, a jar of natural peanut butter, and a box of multi-grain cereal from Kashi. Great nutritional meals are focused around a lean protein (the tuna), and some combination of a complex carb (Kashi cereal), and a healthy fat source (peanut butter). I've also become so starchy carb-sensitive that even one peice of white bread will basically knock me out for an hour. When I had access to hospitality suite food, I had two hamburger patties, both with a slice of cheese and ditched the bun. Maybe not the ideal meal, but when you're on the go and eating time is at a premium, sometimes it's all about minimizing the damage (ie - starchy carbs, breads, potatoes, and sugars).
We all have to do the best we can with foods we like when traveling, and obviously luggage space and travel method play a big role. Here's a blog post by figure competitor Barbara Mencer about her efforts to bring foods on a travel trip to avoid completely wrecking her nutrition while away from home.
I also learned from a few Twitter friends who were traveling to Columbus, OH for the Arnold Sports Festival about freezing chicken breasts and veggies to bring along to the hotel. Like Barbara Mencer, I learned first hand how expensive it can be relying on a hotel for too many of your meals.
I did not get to work out last weekend, mostly due to the strenuous schedule that was kept during the actual work portions of the weekend. Off-time was precious and had to be spent recouperating for the next day. Most hotels will have a fitness room of SOME kind, obviously some hotels will feature better equipment than others. I've reviewed body weight workouts previously, which can be done anywhere (even out in the parking lot if you can find a solitary space).
I had no idea about using the actual hotel room as a make-shift workout facility. Greg Plitt (basically one of the top 3 or 4 fitness models in the business) has a great video on his members website about using your hotel room as a gym when on the road. Here's a preview:
As I have hopefully outlined above, there is no legitimate reason to make the same lazy mistakes I made a year ago in Detroit. With a little preparation and creativity, there is no reason to let a brief road trip derail your fitness goals.