Gap Acceptance and Road safety hazard at unsignalized intersection

Gap Acceptance and Road safety hazard at unsignalized intersection

1. Gap Acceptance and Road safety hazard at unsignalized Intersection 1

2. Gap Acceptance and Road safety hazard at unsignalized intersection National Institute of technology Kurukshetra Department of Civil Engineering SATARUDR PRAKASH under the guidance of (32012421) DR.SN SACHDEVA 2

3. O utlines Introduction Literature Review References 3

4. Introduction:- Over 1,37,000 people were killed in road accidents in 2013 alone, that is more than the number of people killed in all our wars put together One serious road accident in the country occurs every minute and 16 die on Indian roads every hour. 1214 road crashes occur every day in India. Two wheelers account for 25% of total road crash deaths. 20 children under the age of 14 die every day due to road crashes in in the country. 377 people die every day, equivalent to a jumbo jet crashing every day. Tamil Nadu is the state with the maximum number of road crash injuries 4

5. To define the reasons for investing accidents and incidents. There are many reasons for a accident and some of them are:- Behind every reason mention above one of the major cause of accident is impatience and carelessness. 5

6. Gap Acceptance:- The  gap acceptance  happens when the vehicle confidently does the lane change or intersection crossing. The  critical gap  is the smallest  gap  that a driver is willing to accept to merge with the circulating traffic. According to HCM(2000) “ the minimum time in sec. between successive major stream vehicle in which a minor stream vehicle can make a manoeuvre . 6 Problem in heterogeneous traffic Vahicle accept the narrow gap to move parallel with vehicle Minor vehicle do not follow the priority rule.

7. Literature Review S. NO Title Author 1 Multi Vehicle-Type Right Turning Gap-Acceptance and Capacity Analysis at Uncontrolled Urban Intersections Dr. K.V.R. Ravishankar 2 Critical Gap through Clearing Behavior of Drivers at Unsignalised Intersections Ashalatha R.* and Satish Chandra 3 Gap Acceptance Behavior of Drivers at T-Intersections Dr. Bino I Koshi 4 A Review of Critical Gap Estimation Approaches at Uncontrolled Intersection in case of Heterogeneous Traffic Conditions Akhilesh Kumar Maurya 7

8. 1.Multi Vehicle-Type Right Turning Gap-Acceptance and Capacity Analysis at Uncontrolled Urban Intersections Critical gap and follow up time depends on the type of vehicles crossing the intersection. Data was collected from two All-way-stop-controlled (AWSC) intersections in Warangal city, Telangana state, India. The choice has been made to analyse the clear difference between the gap acceptance behaviour because of heavy vehicles and other vehicle types on the major road. 8

9. Line diagram and Modal share for intersection1 Line diagram and Modal share for intersection2 9

10. Gap accepted(is done only for vehicles which are taking right turn from minor to major stream) and rejected, follow-up time for each vehicle type was extracted from the video. The critical gap values obtained from clearing behaviour are compared with Raff’s method. Table 1:- Critical gap observed using the clearing behaviour of vehicles (in seconds) 10

11. Conclusion:- The values of critical gap increased with the size of vehicle The critical gap values obtained from the clearing behaviour method are higher than that obtained from Raff’s method. The values of critical gap obtained by clearing behaviour method gives the safest critical gap values for the vehicle to cross the intersection The values for 2w and 3w are almost double. For tractors, HV, 4w and LCV resulted in large variation in critical gap for minor to major flow. This is because the data size is low for these types of vehicles. 11

12. 2. Critical Gap through Clearing Behavior of Drivers at Unsignalised Intersections Location : Data for this study were collected at 4 three legged right angled intersections in semi-urban areas of Hyderabad in the state of Andhra Pradesh and Thiruvananthapuram in the state of Kerala Data Collection:- Video recording technique. Data was collected in 4 categories car, motorized two-wheeler, three-wheeler and heavy Vehicle using six different methods available in literature Method: Critical Gap through Clearing Behavior. The point of intersection : A situation when clearing time is just equal to the gap or lag accepted (Critical Gap) and they intersect during saturated Traffic 12

13. Fig 1. Schematic Representation of Influence Area for Gap Acceptance for Right Turn from Minor Fig 2 Schematic Representation of Influence Area for Gap Acceptance for Right Turn From Major 13

14. Table 1 Critical Gap Estimated by Different Methods 14 All the six methods tried here were developed under uniform traffic conditions where rule of priority is strictly followed.

15. Table 2 Critical Gap Estimated Using the New Concept Table2 Comparison of Critical Gap Estimated by Proposed and Existing Methods 15

16. Conclusion The critical gaps are estimated for three types of vehicles and two types of movements at two unsignalised T intersections under mixed traffic conditions, using six different methods available in literature. These values are found to be quite low with wide variation (12%-38%) among the values A new concept of critical gap estimation suitable to mixed traffic behaviour. Results from this found to be lower than those given in HCM (2000) but greater than those estimated by existing methods. The critical gap for a car under mixed traffic condition is expected to be lower than that under uniform traffic conditions, mainly due to clearing behavior of vehicles. 16

17. 3. Gap Acceptance Behavior of Drivers at T-Intersections Hypothesis testing is done between Ho: Gaps are equal Ho: Gaps are not equal Bike vs. Car Reject Accept Bike vs. Three wheeler Accept Reject Bike vs. LMV Reject Accept Car vs. Three wheeler Accept Reject Car vs. LMV Accept Reject Three wheeler vs. LMV Reject Accept Male vs. female Accept Reject Male vs. female Reject Accept Middle vs. Elder Accept Reject For data collection the author selected the video recording process. A comparison of gap acceptance by male and female drivers and based on age groups and also based on vehicle classification is carried out by hypothesis testing. 17

18. Critical gap is estimated by plotting accepted gap and rejected gap and is obtained as 5.1s for Tripunithura and 2.8s for Manarcad Conclusion The model formulated by SYSTAT and was validated using mean absolute percentage error and was found to be within the limits. As waiting time increases drivers tends to accept shorter gaps. 18 Critical gap at Manarcad Critical gap at Tripunithara

19. 4. A Review of Critical Gap Estimation Approaches at Uncontrolled Intersection in case of Heterogeneous Traffic Conditions Location:- 4 legged at Ahmedabad with 5 video cameras. Author has done the Comparison between 9 models for gap acceptance calculation. 19

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21. Conclusion: Most of the above method evolved under fully homogeneity. Clearing behavior approach which has been evolved for mixed traffic conditions produces quite reasonable results for both movements. This approach takes the concept of clearing time to incorporate the actual driving behavior of drivers. 21

22. References Ashalatha, R., and Chandra, S. (2011). “Critical gap through clearing behavior of drivers at unsignalised intersections.”  KSCE Journal of Civil Engineering , 15(8), 1427–1434. Abhigna, D., Brahmankar , D. P., and Ravishankar, K. V. R. (2018). “Multi Vehicle-Type Right Turning Gap-Acceptance and Capacity Analysis at Uncontrolled Urban Intersections.” Periodica Polytechnica Transportation Engineering , 48(2), 99–108. 22

23. Amin, H. J., and Maurya, A. K. (2015). “A review of critical gap estimation approaches at uncontrolled intersection in case of heterogeneous traffic conditions.” Journal of Transport Literature , 9(3), 5–9. Dr. Bino I Koshi, and Karthika P T (2014). “Gap Acceptance Behavior of Drivers at T Intersections .” International Journal of Engineering Research & Technology (IJERT ) ISSN: 2278-0181 IJERTV3IS110791Vol. 3 Issue 11 23