Design of Parking Facility
All the vehicles do not keep moving along the roadway during the entire 24 hours of the day; they have to stop or park at the desired locations for different duration’s. In cities the problem of parking vehicles is becoming more and more acute day by day. When vehicles are parked on the road side even for a short while. Therefore, there is restriction to other vehicles passing by, resulting in congestion and accidents. In shopping centres, public places and localities with offices there is a shortage of parking facilities. Proper planning and design of parking facilities is essential in cities and large towns. Details of parking studies including estimation of parking demand. In this Article some particulars pertaining to design of parking facility are providing.
Parking facilities may be broadly divided into two types:
- On-street or kerb parking
- Off-street parking
On-Street or Kerb Parking
Types of kerb parking
In this type of parking, vehicles are park along the kerb which may be designed for parking. Kerb parking is quite convenient for those who find suitable space to park their vehicles near the place they wish. But for others who do not find a parking space it is a problem. Often they may have to park their vehicle at a far off place and walk down to the destination. Unless the kerb parking facility is adequately designing in advance while planning a new town; it might lead to a lot of inconvenience to moving vehicles. This result in congestion at the road stretches due to reduction in road capacity and increase in accidents.
Kerb parking facility may be either unrestricted or restricted type. The restricted kerb parking may either be controlled by police or by parking metres. Therefore, a specified parking fee is collected from those who park their vehicles for a certain duration of parking time.
Different patterns of kerb parking are ‘parallel parking‘ and ‘angle parking‘. The length of parking space required along kerb and roadway width occupied by the parked vehicles for different parking angles. The number of vehicles that can be park per unit length of the kerb.
It needs less roadway width, but number of vehicles that can be parked per unit length of road is least. Parallel parking is generally prefer when the width of kerb parking space and the width of the street are limit. But the parking and unparking operations are more difficult needing a few forward; and reverse movements before parking properly or before taking out. Parallel parking may be either with equal spacing facing the same direction or two cars place closely leaving a gap as open space (for manoeuvring) between two-car units.
Angle parking may be at angles 30, 60 or 90 degrees. The width of the roadway required for parking; also the width required for parking and unparking manoeuvres increase with increase in parking angle up to maximum 90° angle. Angle parking accommodates more vehicles per unit length of kerb; maximum number of vehicles that can be parked per unit length of the kerb is with right angle parking. Angle parking is more convenient to the drivers for the parking and unparking manoeuvres than the parallel parking; however these cause much more obstruction to the through traffic resulting in more accidents than the parallel parking. Out of various angles used for angle parking; degree angle is considering the best taking into account all the above factors.
Need for off-street parking facility
At locations where the parking demand is high and kerb parking cannot be permitting in view of traffic congestion, off-street parking facilities are providing at the nearest locations depending on the availability of space for this purpose. When a parking facility is providing at a separate place away from the roadside or kerb, it is termed as ‘off-street parking’. The main advantage of this method is that there is no undue increase in congestion, delay and hindrance to moving traffic due to on street parking on the already congested roads. But the main drawback is, some of the vehicle users will have to walk a greater distance after parking the vehicle at the off-street parking facility. It is also not possible to provide the off-street parking facility at very close intervals especially in business centres of a city.
Types of off-street parking
Two basic types of off-street parking facilities are, ‘surface parking lots’ and ‘multi-floor parking garages’. Both in the parking lots and the garages, the basic traffic operations consist of five steps namely,
Hence some definite space is requiring in front of the parking lot or garage for vehicles during entrance acceptance and also for exit operations. This space providing is termed as ‘reservoir area’, the size of which depends on the average rate of arrival of vehicles to be park during peak hour. The average time required to dispose off one car and the number of attendants employed for storage-operations. However, for self parking there is no need for the reservoir space, as the additional space requirement at the entrance and exit will be minimum.
Surface parking lots
Surface parking lots may be convenient where sufficient space is available at comparatively low cost. When the parking of vehicles is doing by owners or drivers of the cars, the method is termed “self parking system’. If the vehicle is left by the driver at the entrance space and again collecting from there, the parking and delivering operations being carried out by attendants, it is termed ‘attendant parking system’. Most important advantage of attendant parking is less space requiring to store and manoeuvre the same number of cars.
Multi-storeyed parking garages
Multi-storeyed parking garages are restored to when the floor space available for the parking garage is less and is very costly. It is possible to construct multi-storeyed garages to park a large number of cars at a time. The garages can be above the ground or below the ground or an integral of both. It is necessary to provide the inter-floor travel facility for the vehicles, which may be either by ‘elevators’ or by ‘ramps’.
In mechanised garages the elevator may be designed to move both in vertical and in horizontal directions to carry and place the vehicle in the appropriate parking stall and to deliver it back. The mechanised garages are operated by trained parking attendants only. Therefore the owners/drivers of vehicles will have to hand over the vehicle and the keys to the parking attendant at the reserved space at the entrance; similarly, the vehicle is taking delivery also from the space near the exit. One of the main advantages of mechanised parking garages is parking space requirement is minimum and there is maximum utilisation of available space. The disadvantage of this method is that if there is a mechanical breakdown or a power failure, the functioning of the elevator system would come to a stand-still.
When ramps are providing for driving the vehicles to and from the parking stalls located at different floor levels, the total space requirement will be increased considerably. For self parking, the overall ramp space requiring will be still higher.