SPEED OF VEHICLE USING RADAR GUN

OBJECT: TO ANALYZE THE SPOT SPEED OF VEHICLES ON SELECTED ROADS USING RADAR GUNS.

PERFORMANCE OBJECTIVE:

Upon successful completion of this lab experiment, students will be able to,

1. Define Spot Speed
   
2. Define Various methods of spot speed calculation
   
3. Successfully conduct a spot speed survey
   

APPARATUS

1. Radar speed meter (Radar gun)
   
2. Safety vests
   
3. Measuring wheel
   
4. Clipboard and field data form
   
5. Stopwatch
   

Radar Gun: A radar speed gun (also a radar gun and speed gun) is a device used to measure the speed of moving objects. It is used in law enforcement to measure the speed of moving vehicles.

THEORY:

To analyze the speed and the number of vehicles on a determined road. Spot speed is the average speed of vehicles passing a point, or the time mean speed. Spot speed studies are conducted to estimate the distribution of speeds of vehicles in the stream of traffic at a particular location on a highway. Carried out by recording the speeds of a sample of vehicles at a specified location. Spot speed studies are used to determine the speed distribution of a traffic stream at a specific location. The data gathered in spot speed studies are used to determine vehicle speed percentiles, which are useful in making many speed-related decisions.

PROCEDURE

1. Perform necessary preparations such as sufficient pens or pencils, radar meter spot speed study data forms, and clipboards; ensure the radar speed meters are in good condition; read instructions for the used radar gun; obtain a power battery; ensure safety; and others.
   
2. Decide on study location. The selected site should be a straight and level road section that represents different traffic conditions.
   
3. Enumerators should arrive 30 minutes earlier at the side to familiarize themselves with a visual survey before selecting a strategic location. The equipment shall be distributed, and the general information of the speed spot data recording forms shall be filled that comprise the observer’s name, time, date, name of site, posted speed limit, and weather condition and begin at the planned time.
   
4. The layout of the study area was sketched with the description of chosen reference points, position of observation, number of lanes, and road class.
   
5. The enumerators, the radar unit, and the station for speed data collection should be inconspicuous where possible so that vehicular speeds are significantly not affected by the data collection activities.
   
6. Select samples randomly; for example, the observer recorded a speed reading for every third vehicle or every fifth vehicle.
   
7. The radar meter should be made as direct a line with oncoming traffic as possible, meaning to make it as close to the roadway as possible (an exception when the vehicles are selected and the radar unit tends to affect vehicles’ speeds considerably.)
   
8. Record slash on the speed data sheet corresponding to the speed observed for each selected vehicle under the appropriate vehicle-type classifications.
   
9. The vehicle speeds were observed for the 100 samples.
   

Speed Data Reduction and Analysis After the study is completed and the data have been tabulated, the following steps may be considered as part of the typical data analysis. Specifically, the idea would be to identify key Parameters associated with roadway speeds, which may include any or all of the following:

• Mean Speed: The average speed is calculated as the sum of all speeds divided by the number of speed observations.
• 85th Percentile Speed: The speed at or below which 85 percent of a sample of free-flowing vehicles is traveling; this is typically used as a baseline for establishing the speed (Based on a spot speed study)

• 95th Percentile Speed: The speed at or below which 95 percent of a sample of free-flowing vehicles is traveling (based on a spot speed study)

• Median (50th Percentile Speed): The speed that equally divides the distribution of spot speeds; 50 percent of observed speeds are higher than the median; 50 percent of observed speeds are lower than the median.

• Mode: The number that occurs most frequently in a series of numbers.

• Speed Variance: The difference in travel speeds for vehicles on the road.

Mathematically, variance is the average of the squares of the difference to the mean for each observed speed.

• Pace: A 10-mile-per-hour increment in speeds that encompasses the highest portion of observed speeds; often is the mean speed plus/minus five miles per hour (19).

OBSERVATION TABLE:

Group Activity: Select a road in the vicinity of your city and calculate the speed of at least 30 vehicles using a radar gun.