It can be to an extent. I drove through Hyde Park my fair share of times when coming home from my previous job and if you catch it at the right times during rush hour, you'll deal with some pretty clogged roads. Route 9 in particular really slows down due to volume in near the central part of the town (near Roosevelt, the restaurants and diners, etc.), and traffic lights add to the travel time.
I can't say I ever experienced slow-crawl, bumper-to-bumper traffic like you'd find in New York City, but these are one-land roads after all and it's a growing area. All it takes is one car going slowly during rush hour through there and there'll be a long string of cars piled up behind them.
Still, is it always a problem? No. Aside from rush hour or the daytime hours on weekends, traffic through Hyde Park is pretty manageable.
