Experienced superhighway drivers know the importance of staying behind or ahead of what some people call wolf packs –- several fast-moving vehicles bunched together. Wolf-packing can be the cause of high-speed fatalities.

This passage was probably written for people who are:
a. vehicle inspectors
b. new drivers
c. traffic officers
experienced drivers

Only one group of drivers probably doesn't know this. Which group is that?

b. new drivers

The passage was probably written for experienced drivers. This can be inferred from the statement "Experienced superhighway drivers know the importance of staying behind or ahead of what some people call wolf packs." This suggests that the information is intended for drivers who already have experience on the superhighway and are familiar with the concept of wolf packs. Vehicle inspectors, new drivers, and traffic officers may not necessarily have the same level of knowledge or experience in this context.