1. A lot of companies have a small or no data science team. So a lot of work is contracted. Contractors can be at 75%+ travel if they are not local.

2. Companies that sell software with "advanced analytic" (e.g. R) capabilities that is customized for customers. There are also companies that sell prebuilt solutions for specific use cases (e.g. oil production analysis analysis) where the core R/Python scripts are already built, but they have to integrate with customer's IT infrastructure and validate output. Closer to 50% travel (this includes sales and services).

3. Some large (e.g. 30,000+ employees) companies have data science teams that are tasked with helping the rest of the company run better. They don't focus on one area. Rather, they visit different divisions and evangelize and create data science for better operations. They operate almost like internal contractors when conveying their value to upper management. Travel up to 25% since different divisions can be spread across a country or even the world.

Now my caveat. Most of what I've described are describing positions for data science generalists, not experts in one specific area (e.g. looking at price elasticity in consumer goods). From what I've seen on job sites, a lot of more focused data science positions are in advertising (or related) and deep data mining of people. I typically don't focus on these jobs so I'm missing data on a lot of 0-5% travel positions.