Transportation Engineerng Lab Spot Speed Survery.pptx

about transportation engineering

1. Experiment No. 8: Spot Speed Survey Department of Civil Engineering IIT Bombay CE 328 Transportation Engineering Lab Teaching Assistant: Pravin Telang

2. Application Speed is one of the fundamental parameters of Transportation Engineering which is used in the following aspects. In designing geometric features of roadway To calculate the traffic flow and traffic capacity For understanding the causes of accidents To study the effect of enforcements For traffic regulation and management To define speed limits To establish safe speeding zones To design signals

3. Source:- https://www.hindustantimes.com/mumbai-news/maharashtra-traffic-police-to-spend-50-crore-on-high-tech-equipment-for-road-safety/story-Ueb5HsuLG00wi7ngpZzZuM.html

4. Equipment: Radar Gun Radar Guns work on the doppler effect. It can be hand-held and easy to use Radio signals are emitted from the guns and then the gun receives it after bouncing off the object. Radar Gun is kept at an angle within 20 degrees. Approximate distance from the vehicle 30 meters. Accuracy: ± 1.5 to 3 kmph

5. Aim of the Experiment To find the spot speed of the vehicles on a mid-block section and, Calculate the time mean speed and space mean speed Find the 15 th percentile speed, 50 th percentile speed and 85 th percentile speed.

6. Time Mean Speed It is the average speed of the flow crossing a particular point over a duration of time. It is the arithmetic mean of spot speed. ;   Space Mean Speed It is the average speed of the flow over a particular stretch of road at a particular time period. It is the harmonic mean of spot speed.   where v i is the spot speed of i th vehicle

7. Fundamental Relation of Traffic where, is the flow of vehicles (in veh/hr) is the density of vehicles on road (in veh/km) is the space mean speed of vehicles (in km/hr)  

8. Percentile Speeds 85 th percentile speed is chosen for design of sight distance and for the radius of the circular curve on the road. Speed Limits shown on the road are basically 85 th percentile speed. 98 th percentile speed limit are used to design the road. 15 th percentile speed is the minimum speed on the road.

9. Procedure At the given location please stand in a such way that the angle between the vehicle’s motion and angle of radio waves should be less than 20 degrees. From the observed spot speed, calculate the time mean speed and space mean speed. Make a frequency table of spot speed. Calculate the cumulative frequency and plot the graph for the same. From the graph mark the 15 th , 50 th , and 85 th percentile speed.

10. Groups Four groups will be made In each group, every person will take 5 readings of spot speed. All the groups will perform the experiment on the main gate road at different locations. Spot Speed (kmph) 32 26 45 2 2 9 4 5 33 22 19

11. Observation Table Lower Limit Speed (kmph) Upper Limit Speed (kmph) Mid value Speed (kmph) Number of vehicles (of 100) Frequency (%) Cumulative Frequency (%) 20 2 5 22.5 2 2% 2% 2 5 3 2 7.5 8 8% 10% 30 35 32.5 5 5% 15% .. .. .. ..

12. Important Notice Next week on 21 st October Saturday there will be A report evaluation doubt clearing session, Quiz on spot speed experiment, and Make up lab for only those who are eligible. The exact timing and venue will be updated soon. Collect your files by Friday (20 th October) evening.

13. THANK YOU