Sioux Falls sits where I-29 and I-90 meet, and the interstates frame the city more than they cross it. I-29 runs north and south along the west side, I-90 skirts the north edge on its way between Rapid City and Minnesota, and I-229 curves around the south and east sides to tie the two together. Veterans Parkway adds a newer route along the growing east side. Inside that frame, most trips run on a grid of arterials: 41st Street through the south-side retail corridor, Minnesota Avenue and Cliff Avenue north to south, and Western, Louise and Sycamore filling in between.
For a mobile mechanic, the layout is friendly. The city is compact enough that a driveway in Cathedral, a lot off 26th Street and a cul-de-sac in the southwest growth areas are all a short drive apart, and the grid rarely forces long detours. Breakdowns tend to cluster in predictable places: the I-229 interchanges at Minnesota Avenue and Cliff Avenue during rush hour, the crowded stretch of 41st Street near I-29, and the ramps onto I-90 on the coldest mornings, when a weak starter finally gives up.
Sioux Falls Regional Airport sits on the north side, close to where I-29 and I-90 meet, so its parking lots are a common stop for a car that won't start after a trip. Sioux Area Metro runs city bus routes, but most people drive everywhere, which is exactly why having the repair come to the car saves a day. The Big Sioux River loops through the city and past Falls Park, and the bridges over it make handy landmarks when you describe where the car is.