In the past month, I driven quite a bit and my body has felt the effects of that. Getting out of the car feeling hunch over with tight hips and a locked back are symptoms that that I'm sure a lot of people have felt. Getting rid of those symptoms and back to normal seem to be a slow process.
The main areas that are needed to be addresses after sitting for a while whether for work or for traveling are hip flexor mobility, thoracic mobility, and rotary stability. For athletes, it is also important and arguably more important. Athletes, traveling for away games, sitting on the bus or the airplane, who are physically locked up and trying to play at full speed, will not play optimally and put their body's at a greater risk of injury.
But there is a solution to the problem. Try the following three exercises after sitting for a while, whether from work or from traveling. If one side on your body feels more restricted then spend more time on that side. This asymmetry is what will hinder a person.
Hip flexor stretch
Assume a half kneeling position, tuck the hips under, posteriorly tilting the pelvis, and stay tall through your spine. Don't worry about timing yourself with a watch but perform 20 slow diaphragmatic breathes then switch sides.
Open book stretch variation
Lay on your back as if you were to do a sit-up. Keep your feet and knees together, roll to one side keeping the hips and shoulders stacked and arms stretched out in front of you. Your knees must stay connected and touching the ground. Take your top hand and trace the floor over your head making a semi-circle. The goal is knees, shoulders, and arms on the ground in the finished position. Return to start position tracing the ground.
Assume a quadruped position with hands under the shoulders, knees under the hips, ankles dorsiflexed and spine neutral. Keeping the hips level and spine neutral, push your left arm out in front of you and drive your right heel behind you. The finished position, from the side, should look like a straight line from your left hand to right heel. Return to start and repeat with your other arm and leg.
Hip Flexor Stretch: 20 breathes each side
Open book Stretch variation: 10 turns each side
Bird Dog: 20 reps total
Give it a try next time and see how fast you feel like yourself again.