Boise sits where the Boise River leaves the foothills and spreads into the Treasure Valley. I-84 runs along the south side of the city past the airport, and I-184, known locally as the Connector, branches off it into downtown. Eagle Road, part of SH 55, is the north-south commercial spine on the west edge, and SH 55 continues north toward Horseshoe Bend and McCall. Chinden Boulevard carries US 20/26 west through Garden City toward Caldwell, and SH 21 follows Warm Springs Avenue east past Lucky Peak toward Idaho City.
Inside the city, State Street, Fairview Avenue, Overland Road and Franklin Road carry the east-west traffic, and Vista Avenue climbs the Bench to the airport. The Connector, the Eagle Road corridor and the I-84 stretch toward Meridian are where weekday breakdowns cause the most trouble. On surface streets, the mile-road grid of the west side makes most homes easy for a mechanic to reach, while the older North End and East End streets are narrower and slower. Snow days slow everything, and the hills of the North End and the Bench can turn icy before the flat west side does.
Boise Airport shares its runways with Gowen Field, home of the Idaho Air National Guard, and its long-term lots see plenty of no-starts after cold weeks. Valley Regional Transit buses connect downtown with the Bench and the west side, and the Greenbelt along the river is a popular way to commute by bike while a car gets fixed at home.