Body-side steps

Body-side steps, more commonly known as running boards or side steps, are narrow horizontal platforms fitted along the lower edge of a vehicle's body beneath the doors. They run roughly the length of the door openings, level with or just below the sills, and provide an intermediate foothold between the ground and the floor of the cabin. They are characteristic of tall vehicles — large SUVs, pickup trucks, vans and off-roaders — whose floor height places the seats well above comfortable stepping distance for many people.

Their purpose is straightforward but genuinely useful. A high-riding vehicle can require an occupant to lift a foot to knee height or more simply to climb aboard, which is awkward at best and a real obstacle for some. The step breaks that single large rise into two smaller ones: the occupant places a foot on the board, transfers their weight, and steps up again into the seat. This makes entry and exit considerably easier and steadier, and it is especially helpful for children, for shorter adults, for elderly passengers and for anyone with reduced mobility. The board also offers a place to stand when reaching items on a roof rack or loading a tall load bed.

The earliest running boards were a near-universal feature of cars in the first decades of the motor age, when high ground clearance and tall bodywork were the norm and the boards also helped keep mud and road spray off occupants' clothing. As cars grew lower and more aerodynamic through the middle of the twentieth century the feature largely disappeared from ordinary saloons, surviving mainly on commercial and utility vehicles. The rise of the SUV and the modern crew-cab pickup brought it back into widespread use, now as much a styling and accessory item as a functional one.

Most side steps are fixed, fabricated from steel, aluminium or moulded composite and bolted to the chassis or body structure. A more sophisticated variant is the powered or retractable running board, which deploys outward and downward automatically when a door is opened and folds neatly back under the sill once the doors are closed. These tuck the step out of the airflow and out of harm's way when driving, preserving ground clearance and reducing aerodynamic drag and the tendency of fixed boards to collect mud, while still presenting a foothold exactly when it is needed.

There are practical trade-offs to weigh. Fixed boards reduce ground clearance and can compromise off-road ability, they can become slippery when wet or icy, and they add weight and a surface that gathers dirt. Powered versions add cost, electrical components and motors that can fail or jam with debris and salt. Genuine running boards should also be distinguished from purely cosmetic trim and from rock sliders, the heavier rails fitted to serious off-road vehicles to protect the sills from damage rather than to assist entry.