the hotel. It was demolished in 2005 after failing to receive landmark status from the city of Chicago. A 49-story apartment tower, 215 West, has taken its place, also featuring a parking garage. When the Capital Garage in Washington, D.C. was built in 1927, it was reportedly the largest parking structure of its kind in the country. It was imploded in 1974. Design The movement of vehicles between floors can take place by means of: interior inclined parking ramps and express ramps without parking – common interior circular/helical express ramps exterior ramps – which may take the form of a circular/helical ramp vehicle lifts (or elevators) – the least common automated robot systems – combination of ramp and elevator Where the car park is built on sloping land, it may be split-level or have sloped parking. Many parking structures are independent buildings dedicated exclusively to that use. The design loads for car parks are often less than the office building they serve (50 psf versus 80 [100] psf), leading to long floor spans of 55–65 feet that permit cars to park in rows without supporting columns in between [called long span]. Podium parking below High/Mid rise buildings are often short span 25–30 feet clear between columns, since office/residential/retail floors above require more support [100 psf per International Building Code]. Columns in short span structures obstruct row based parking spaces and will be less efficient than long span designs; parking efficiency is measured in cars per level square footage [car count/level area]. Common structural systems in the United States for long span structures are prestressed concrete double-tee floor systems, post-tensioned cast-in-place concrete floor systems or short span podium parking with post tensioned slabs and drop panels [drop heads. Steel embeds or thicker slabs can eliminate the need for drop panels, providing higher clearances for higher profile vehicles.] In recent times, parking structures built to serve residential and some business properties have been built as part of a larger building, often underground as part of the basement, such as the parking lot at the Atlantic Station redevelopment in Atlanta. This saves land for other uses (as opposed surface parking), is cheaper and more practical in most cases than a separate structure, and is hidden from view. It protects customers and their cars from weather such as rain, snow, or hot summer sunshine that raises a vehicle's interior temperature to extremely high levels.