A turning bay is the area at the end of a parking bay in a parking structure where drivers make a 180-degree turn into the next bay or onto a ramp to change levels.
In most parking structures, drivers travel down one parking bay, turn at the end, and travel back along the next. The turning bay is where that turn happens. Its width is usually set by the parking module, the width of two rows of stalls plus the drive aisle between them, and its geometry decides how easily drivers, and especially larger vehicles, can make the turn without backing up or clipping columns and parked cars.
What shapes a turning bay
- Module width. A wider module gives a wider, easier turn; a tight module forces sharper turns and slower traffic.
- Stalls in the turn. Corner stalls inside the turning path are often eliminated, restricted to compact cars, or angled, which costs capacity.
- Columns and walls. Column placement at the ends of the bays can pinch the turn, so long-span framing helps here.
- Design vehicle. Turning paths are checked for the largest vehicle the garage must serve, often with software such as AutoTURN.
- Sight lines. Drivers turning blind around a wall or ramp need visibility to pedestrians and oncoming cars.
Where problems show up
- Scuffed walls, damaged columns and curbs at the ends of bays are a sign the turning bay is too tight for the vehicles using it.
- Two-way traffic in a turning bay creates conflicts; many garages make end bays one-way.
- Larger pickups and SUVs have made some older turning bays harder to use than when they were designed.
The Parkonomics view
The turning bay is where a garage either feels easy or feels like work. It is tempting to squeeze a few more stalls into the ends of the bays, but every driver passes through those turns, often several times per visit. Size them for today’s larger vehicles and keep columns out of the turn.
Related terms: Parking Geometry, Parking Module, Single Helix, Double Helix, AutoTURN
Further reading: The Evolution of U.S. Parking Structures in 2026