Bozeman sits at the head of the Gallatin Valley, ringed by the Bridger and Gallatin ranges, and its highways follow the valleys out of town. I-90 runs along the north side of the city, heading west toward Belgrade and Three Forks and east over Bozeman Pass toward Livingston. US 191 runs southwest through Four Corners and up Gallatin Canyon toward Big Sky and West Yellowstone. MT 86 climbs Bridger Canyon toward the ski area, and MT 85 connects Belgrade with Four Corners. Huffine Lane carries traffic west toward Four Corners, North 19th Avenue is the main north-south commercial corridor, and Main Street runs through the historic downtown.
Bozeman has grown fast, and its roads haven't always kept pace. North 19th Avenue, Huffine Lane and the I-90 interchanges back up at rush hour, and traffic between Bozeman, Belgrade and Four Corners is heavy most of the day. Bozeman Pass and Gallatin Canyon are where many highway breakdowns happen, especially in winter, when wind on the pass drifts snow and the canyon road turns icy. Construction zones are a fixture on the main corridors in the warm months, adding lane shifts and delays.
Bozeman Yellowstone International Airport is in Belgrade, west along I-90, and its lots see plenty of no-starts after a winter trip. Streamline buses connect Bozeman, Belgrade and the university, but most people drive.
Deer and elk are common on the roads around Bozeman, especially at dawn and dusk in fall and winter, and wildlife collisions are a frequent cause of front-end damage. Many locals ease off the speed on rural roads after sunset for exactly that reason.