Other drawbacks include longer length, which limits their turning radius and ability to use some lifts or wheelchair-designed access technologies such as kneeling bus lifts. The longer length may also make it difficult to reach door-opener buttons or doorknobs. Some mobility scooter have low ground clearance which can make it difficult to navigate certain obstacles, such as travelling in cities without proper curb cuts (aka dropped kerbs). Navigating in restricted spaces, whether in the home or in public spaces and buildings, can also be a problem.