What is parking studies in traffic engineering?
Parking is one of the major problems that is created by the increasing road traffic. It is an impact on transport development. The availability of less space in urban areas has increased the demand for parking space especially in areas like the central business districts.
Before taking any measures for the betterment of conditions, data regarding the availability of parking space, an extension of its usage and parking demand is essential. It is also required to estimate the parking fares also. Parking surveys are intended to provide all this information.
The most common parking surveys conducted are in-out survey, fixed period sampling and license plate method of survey.
1) In-out survey:
In this survey, the occupancy count in the selected parking lot is taken at the beginning. Then the number of vehicles that enter the parking lot for a particular time interval is counted. The number of vehicles that leave the parking lot is also taken.
The final occupancy in the parking lot is also taken. Here the labour required is very little. Only one person may be enough. But we won’t get any data regarding the time duration for which a particular vehicle used that parking lot. Parking duration and turnover is not obtained. Hence we cannot estimate the parking fare from this survey.
Fixed period sampling:
This is almost similar to the in-out survey. All vehicles are counted at the beginning of the survey. Then after a fixed time interval that may vary between 15 minutes to 1 hour, the count is again taken. Here there are chances of missing the number of vehicles that were parked for a short duration.
2) License plate method of survey:
This results in the most accurate and realistic data. In this case of a survey, every parking stall is monitored at a continuous interval of 15 minutes or so and the license plate number is noted down.
This will give the data regarding the duration for which a particular vehicle was using the parking bay. This will help in calculating the fare because the fare is estimated based on the duration for which the vehicle was parked. If the time interval is shorter, then there are fewer chances of missing short-term parkers. But this method is very labour-intensive.
Effects of parking
Parking has some ill-effects like congestion, accidents, pollution, obstruction to fire-fighting operations etc.
Congestion: Parking takes considerable street space leading to the lowering of the load capacity. Hence, speed will be reduced, journey time and delay will also subsequently increase. The operational cost of the vehicle increases leading to great economic loss to the community.
Accidents: Careless manoeuvring of parking and unparking leads to accidents which are referred to as parking accidents. A common type of parking accident occur while driving out a car from the parking area, the careless opening of the doors of parked cars, and while bringing in the vehicle to the parking lot for parking.
Environmental pollution: They also cause pollution to the environment because stopping and starting vehicles while parking and unparking results in noise and fumes. They also affect the aesthetic beauty of the area
Obstruction to fire fighting operations: Parked vehicles may obstruct the movement of firefighting vehicles, Sometimes they block access to hydrants and access to buildings.
Types of Parking
1) On street parking
On-street parking means the vehicles are parked on the sides of the street itself. This will be usually controlled by government agencies themselves. This type of parking was allowed in Durbarmarg. Common types of on-street parking areas are listed below. This classification is based on the angle at which the vehicles are parked with respect to the road alignment.
A) Parallel parking:
The vehicles are parked along the length of the road. Here there is no backward movement involved while parking or unparking the vehicle. Hence, it is the safest parking from the accident perspective.
However, it consumes the maximum kerb length and therefore only a minimum number of vehicles can be parked for a given kerb length. This method of parking produces the least obstruction to the on-going traffic on the road since the least road width is used.
B) 30° Parking
In thirty-degree parking, the vehicles are parked at 30° with respect to the road alignment. In this case, more vehicles can be parked compared to parallel parking. Also, there is better manoeuvrability. Delay caused to the traffic is also minimum in this type of parking.
C) 45° Parking
As the angle of parking increases, more vehicles can be accommodated in this type of parking.
D) 60° Parking
The vehicles are parked at 60° in the direction of the road. More number of vehicles can be accommodated in this parking type. But lateral distance required for parking will also be increased.
E) Right angle parking:
In right angle parking or 90′ parking, the vehicles are parked perpendicular to the direction of the road. Although it consumes maximum width kerb length required is very little.
In this type of parking, the vehicles need complex maneuvring and this may cause severe accidents. This arrangement causes obstruction to the road traffic particularly if the road width is less.
However, it can accommodate the maximum number of vehicles for a given kerb length. An example is shown in figure 38:6. Length available for parking N number of vehicles is L= 2.5N.
On street parking should be prohibited at:
The parking on the narrow roads cause difficulties in traffic flow. Hence the on-street parking of two-way roads less than 5.75m items wide and less than 4 m wide one-way roads should be prohibited.
To prevent in reduce invisibility and capacity of intersections, on-street parking should not be done near intersections.
Structure: As the parking on road structures such as bridges, culverts etc. reduces their capacity, on-street parking on such structures should be prohibited.
Entrance driveway: On-street parking at the entrance, a driveway may cause obstacles for proper movement. Hence they should be prohibited.
2) Off street parking
In many urban centres, some areas are exclusively allotted for parking which will be at some distance away from the mainstream of traffic. Such parking is referred to as off-street parking. They may be operated by either public agencies or private firms. A typical layout of off-street parking is shown in the figure.
Types of off street parking
- Surface car Parking
- Multi-storey parking
- Roof Parking
- Underground parking
- Surface car Parking
It may be convenient where sufficient space is available at a comparatively low cost. The vehicle is left by the driver at the parking space. There may be a fee-charging system for proper parking management.
2. Multi-Storey parking :
When the floor space available for the parking is less and very costly, multi-storey parking is constructed. The garage inter-floor travel facility for the vehicle may be either by elevators or by the lamp.
3. Roof parking:
As there may be space available on the roof of the building which can be used to park the vehicles. Access may be provided by elevator or ramp. It is a popular method of parking as no extra space for parking should be arranged as the top of the building is used as parking.
4. Under-ground parking:
It is commonly used in multistorey buildings in a built-up areas. In this method, the underground floor is used as parking. Hence there will be no need of extra land for parking. But the construction of underground parking is very costly.
I hope this article remains helpful for you.
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