Vehicle Dynamics and the Slalom Course
If there is one exercise that appears in most all EVOC programs it would be the slalom course. Driving through a slalom creates an abundance of teaching points, one of them is the effect of vehicle speed on the decision-making process.
The following are some examples of how that can be accomplished.
Examples
The students speed through a slalom where the cones are separated by 60 Feet is 30 MPH. The first step is to convert is the speed, 30 MPH, to Feet Per Second. This is done by multiplying the 30 MPH by 1.5, which will equal 45 FPS.
Step 1 Convert the MPH to Feet Per Second (FPS)
30 MPH x 1.5 = 45 FPS
For more information on converting Miles Per Hour to Feet Per Second read Explanation of Time.
The second step is to take the distance between cones, which is 60 Feet, and divide it by the speed converted to FPS which is 45 FPS.
Step 2 Divide the distance between the cones (60 Feet) by the FPS which is 45
60 Feet/45 FPS = 1.33 Seconds
Result
The result is, a student moving at 30 MPH, through cones separated by 60 Feet, consumes 1.33 seconds to complete the task of driving from cone to cone.
Increasing the Speed
The same slalom course – the instructor increases the speed to 35 MPH.
Step 1 Convert the MPH to Feet Per Second (FPS) – speed is now 35 MPH
35 MPH x 1.5 = 52.5 FPS
Step 2 Divide the distance between the cones (60 Feet) by the FPS (52.5)
60 Feet/52.5FPS = 1.1 Seconds
The result is, a student moving 35 MPH, through cones separated by 60 Feet, consumes 1.1 seconds to complete the task of driving from cone to cone.
Increase the speed to 40 MPH
The same slalom course, increase the speed to 40 MPH
Step 1 Convert the MPH to Feet Per Second (FPS) – speed is now 40 MPH
40 MPH x 1.5 = 60 FPS
Step 2 Divide the distance between the cones (60 Feet) by the FPS (60FPS)
60 Feet/60 FPS = 1 Second
The result is, a student moving 40 MPH, through cones separated by 60 Feet, consumes 1 second to complete the task of driving from cone to cone.
The level of difficulty from 30 MPH to 35 MPH has increased significantly. The level of difficulty from 30 MPH to 40 MPH has increased to a close to impossible scenario.
In the given scenario, a student driving through a slalom where the cones are separated by 60 Feet and they increase their speed in 5 MPH increments the results will be:
A change of speed 5 MPH (30 to 35 MPH) or. 23 seconds change the outcome significantly, and a change of 10 MPH (30 to 40 MPH) or. 33 seconds make for an impossible scenario to overcome.
See the links below more information on speed and decision time.
Reaction Time
As a note to ensure accuracy, speed should be measured with a radar gun.
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