Effect of traffic flow on the release of pollutant gases
The materials required for this science fair project:
- Highway route with speed limit of 90km/h
- 1 video camera with a stand
- Raised location to set the camera up and to view traffic
- 1 stopwatch
1. For this science fair project, the independent variable is the time of the day traffic is monitored. The dependent variables are the vehicle speed, traffic volume and traffic flow. This is determined by observing the video recording. The constants (control variables) are the chosen location, the day of the observation and the viewing range of the video recording.
2. Choose a raised location along a highway with a 90km/h speed limit. Set up the video camera and adjust it to capture an unobstructed view of a 200m stretch of the highway.
3. Set the timer in the video camera to start at 6:00am and to finish at 12:00 midnight. After the 18-hour recording is completed, analyze the recording.
4. Divide the recording into 6 time windows of 3 hours each, namely, 6am to 9am, 9am to 12pm, 12pm to 3pm, 3pm to 6pm, 6pm to 9pm and 9pm to 12am.
5. From the video, observe the following:
a. Traffic speed – use the time taken by the vehicles to travel the 200m to estimate the vehicle speed.
Speed = 60 x 200 m / (time for 200m in minutes)
Use the formula above and record your results in the table below.
b. Traffic volume – use the number of vehicles on the road to define traffic volume. If there are more than 300 vehicles on the road within the 3 hour window, consider the traffic as high; otherwise, consider it moderate.
c. Traffic flow – consider continual movement of traffic as “smooth”, and traffic that moves, stops and idles as “halting”.
6. Assign numerical values to the observations recorded in step 5, as follows:
a. Traffic speed
1- Value = 1 when speed is between 55 and 75 km/h (this indicates less emissions)
2- Value = 2 in the case of other speeds (this indicates higher emissions)
b. Traffic volume
1- Value = 1 when there is moderate traffic volume
2- Value = 2 when there is high traffic volume
c. Traffic flow
1- Value = 1 when there is smooth-flowing traffic
2- Value = 2 when there is halting traffic
Be careful of road vehicles - Adult supervision required.