Parking is one of the major problems that is created by the increasing road traffic. It is an impact of transport development. The availability of less space in urban areas has increased the demand for parking space especially in areas like Central business district. This affects the mode choice also. This has a great economical impact.
On street parking means the vehicles are parked on the sides of the street itself. This will be usually controlled by government agencies itself. Common types of on-street parking are as listed below. This classification is based on the angle in which the vehicles are parked with respect to the road alignment. As per IRC the standard dimensions of a car is taken as 5× 2.5 meters and that for a truck is 3.75× 7.5 meters.
The length available to park N number of vehicles, L =
In many urban centers, some areas are exclusively allotted for parking which will be at some distance away from the main stream of traffic. Such a parking is referred to as off-street parking. They may be operated by either public agencies or private firms. A typical layout of an off-street parking is shown in figure 6.
There are some minimum parking requirements for different types of building. For residential plot area less than 300 sq.m require only community parking space. For residential plot area from 500 to 1000 sq.m, minimum one-fourth of the open area should be reserved for parking. Offices may require at least one space for every 70 sq.m as parking area. One parking space is enough for 10 seats in a restaurant where as theatres and cinema halls need to keep only 1 parking space for 20 seats. Thus, the parking requirements are different for different land use zones.
Parking has some ill-effects like congestion, accidents, pollution, obstruction to fire-fighting operations etc.
Before taking any measures for the betterment of conditions, data regarding availability of parking space, extent 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 these information. Since the duration of parking varies with different vehicles, several statistics are used to access the parking need. The following parking statistics are normally important.
![]() | (1) |
![]() | (2) |
![]() | (3) |
To illustrate the various measures, consider a small example in figure 7, which shows the duration for which each of the bays are occupied(shaded portion). Now the accumulation graph can be plotted by simply noting the number of bays occupied at time interval of 15, 30, 45 etc. minutes is shown in the figure.
The various measures are calculated as shown below: Parking volume is given as 5
vehicles. Parking load is given as (1 + 2 + 1 + 0 + 1 + 2 + 3 + 1)=
= 2.75 veh hour.
Average parking duration is computed as
= 33 minutes. Parking turnover is
obtained as
= 0.83 veh/hr/bay. Parking index is calculated as
× 100=
45.83%
Parking surveys are conducted to collect the above said parking statistics. The most common parking surveys conducted are in-out survey, fixed period sampling and license plate method of 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 labor required is very less. Only one person may be enough. But we wont get any data regarding the time duration for which a particular vehicle used that parking lot. Parking duration and turn over is not obtained. Hence we cannot estimate the parking fare from this survey. For quick survey purposes, a fixed period sampling can also be done. This is almost similar to 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 i hour, the count is again taken. Here there are chances of missing the number of vehicles that were parked for a short duration.
From an in-out survey conducted for a parking area consisting of 40 bays, the initial count was found to be 25. Table gives the result of the survey. The number of vehicles coming in and out of the parking lot for a time interval of 5 minutes is as shown in the table 1. Find the accumulation, total parking load, average occupancy and efficiency of the parking lot.
Time | In | Out |
5 | 3 | 2 |
10 | 2 | 4 |
15 | 4 | 2 |
20 | 5 | 4 |
25 | 7 | 3 |
30 | 8 | 2 |
35 | 2 | 7 |
40 | 4 | 2 |
45 | 6 | 4 |
50 | 4 | 1 |
55 | 3 | 3 |
60 | 2 | 5 |
Solution The solution is shown in table 2
Time | In | Out | Accumulation | Occupancy | Parking load |
(1) | (2) | (3) | (4) | (5) | (6) |
5 | 3 | 2 | 26 | 65 | 130 |
10 | 2 | 4 | 24 | 60 | 120 |
15 | 4 | 2 | 26 | 65 | 130 |
20 | 5 | 4 | 27 | 67.5 | 135 |
25 | 7 | 3 | 31 | 77.5 | 155 |
30 | 8 | 2 | 37 | 92.5 | 185 |
35 | 2 | 7 | 32 | 80 | 160 |
40 | 4 | 2 | 34 | 85 | 170 |
45 | 6 | 4 | 36 | 90 | 180 |
50 | 4 | 1 | 39 | 97.5 | 195 |
55 | 3 | 3 | 39 | 97.5 | 195 |
60 | 2 | 5 | 36 | 90 | 180 |
1735 | |||||
This results in the most accurate and realistic data. In this case of 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 fare is estimated based on the duration for which the vehicle was parked. If the time interval is shorter, then there are less chances of missing short-term parkers. But this method is very labor intensive.
The parking survey data collected from a parking lot by license plate method is s shown in the table 3 below. Find the average occupancy, average turn over, parking load, parking capacity and efficiency of the parking lot.
Bay | ||||
0-15 | 15-30 | 30-45 | 45-60 | |
1 | 1456 | 9813 | - | 5678 |
2 | 1945 | 1945 | 1945 | 1945 |
3 | 3473 | 5463 | 5463 | 5463 |
4 | 3741 | 3741 | 9758 | 4825 |
5 | 1884 | 1884 | - | 7594 |
6 | - | 7357 | - | 7893 |
7 | - | 4895 | 4895 | 4895 |
8 | 8932 | 8932 | 8932 | - |
9 | 7653 | 7653 | 8998 | 4821 |
10 | 7321 | - | 2789 | 2789 |
11 | 1213 | 1213 | 3212 | 4778 |
12 | 5678 | 6678 | 7778 | 8888 |
Solution See the following table for solution 4.
Bay | |||||||||
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
15 | 30 | 45 | 60 | 15 | 30 | 45 | 60 | Turn over | |
1 | 1456 | 9813 | - | 5678 | 1 | 1 | 0 | 1 | 3 |
2 | 1945 | 1945 | 1945 | 1945 | 1 | 1 | 1 | 1 | 1 |
3 | 3473 | 5463 | 5463 | 5463 | 1 | 1 | 1 | 1 | 2 |
4 | 3741 | 3741 | 9758 | 4825 | 1 | 1 | 1 | 1 | 3 |
5 | 1884 | 1884 | - | 7594 | 1 | 1 | 0 | 1 | 2 |
6 | - | 7357 | - | 7893 | 0 | 1 | 0 | 1 | 2 |
7 | - | 4895 | 4895 | 4895 | 0 | 1 | 1 | 1 | 1 |
8 | 8932 | 8932 | 8932 | - | 1 | 1 | 1 | 0 | 1 |
9 | 7653 | 7653 | 8998 | 4821 | 1 | 1 | 1 | 1 | 3 |
10 | 7321 | - | 2789 | 2789 | 1 | 0 | 1 | 1 | 2 |
11 | 1213 | 1213 | 3212 | 4778 | 1 | 1 | 1 | 1 | 3 |
12 | 5678 | 6678 | 7778 | 8888 | 1 | 1 | 1 | 1 | 4 |
Accumulation | 10 | 11 | 9 | 11 | |||||
Occupancy | 0.83 | 0.92 | 0.75 | 0.92 | 2.25 | ||||
Columns 1 to 5 is the input data. The parking status in every bay is coded first. If a vehicle occupies that bay for that time interval, then it has a code 1. This is shown in columns 6, 7, 8 and 9 of the table corresponding to the time intervals 15, 30, 45 and 60 seconds.
Providing suitable parking spaces is a challenge for traffic engineers and planners in the scenario of ever increasing vehicle population. It is essential to conduct traffic surveys in order to design the facilities or plan the fares. Different types of parking layout, surveys and statistics were discussed in this chapter.
I wish to thank several of my students and staff of NPTEL for their contribution in this lecture. I also appreciate your constructive feedback which may be sent to tvm@civil.iitb.ac.in
Prof. Tom V. Mathew
Department of Civil Engineering
Indian Institute of Technology Bombay, India
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Thursday 28 September 2023 11:21:19 AM IST