Results – Weston Road, Lichfield.
Average Speed .
Overall Average Average Speeds
Speed of Vehicles
Acceleration and Deceleration.
Overall Average Average Deceleration 167
Deceleration
Overall Average Average Acceleration 165
Acceleration
From looking at my results, I can see many things. Firstly, I can see that the average speed of vehicles over the first distance was just over the speed limit of 20 MPH for that area. To be specific, just over half of these vehicles were actually within the set speed limit upon entering the traffic calming measure. Over the traffic calming measure, speeds of these vehicles reduced by an average of 6.68 MPH, meaning the traffic calming measure had done its job correctly as speeds of these vehicles reduced and thus were back within the set speed limit of 20 MPH. Upon exiting the traffic calming measure, the number of vehicles within the set speed limit increased by three meaning that the measure had done its job successfully due to the average speed over the measure was within the set speed limit.
Results – Cherry Orchard, Lichfield.
Average Speed Graph.
Overall Average Average Speeds
Speed of Vehicles
Acceleration and Deceleration.
Overall Average Average Deceleration 154
Deceleration
Overall Average Average Acceleration 140
Acceleration
From looking at my results, I can see many things. Firstly, I can see that the average speed of vehicles over the first distance was well within the set speed limit of 30 MPH for that area. To be specific, all vehicles were on average, 10 MPH under the speed limit when entering the measure. Also, every vehicle that we recorded was within the set speed limit upon entering the measure. Over the traffic calming measure, speeds of these vehicles reduced by an average of 5.6 MPH, meaning that not only has the traffic calming measure done its job successfully, all vehicle were within the set speed limit of 30 MPH, and on average were traveling over half that speed. Upon exiting the traffic calming measure, the number of vehicles within the set speed limit was still at 25 meaning that the measure had done its job successfully due to the average speed over the measure was still within the set speed limit.
Analysis
Overall, and by looking at my results, I can see straight away that the sleeping policemen on Cherry Orchard were more effective than the speed cushions on Weston Road. Firstly, the sleeping policemen were more successful because the overall average speed in Cherry Orchard was nearly 2 MPH lower than that in Weston Road. Also, the amount of vehicles that kept to the speed limit before and after the traffic calming measure a lot higher in Cherry Orchard than in Weston Road. All vehicles keeping to the speed limit in Cherry Orchard show this, whereas there was only an increase of three in Weston Road. Finally, the overall deceleration approaching the sleeping policemen was more than that off approaching the cushions, meaning that the overall success rate of the sleeping policemen is a lot higher than the cushions, and thus, sleeping policemen are more effective as they cover the whole width of the road and cannot be avoided, whereas cushions do not and are easier to avoid.
So in answer to my first aim, I have found that sleeping policemen are the most effective traffic calming measure out of the two methods. Also, I think that my hypothesis has been answered as I have found that sleeping policemen are more successful than the speed cushions. I like to suck cock
Aim 2 – Effectiveness of Sleeping Policemen.
From looking at the table, I can see that larger vehicles are greater effected by the Sleeping Policemen and overall have to have a larger reduction in speed compared to smaller vehicles when coming up to and going over the traffic calming measure. I can see this as the larger vehicles, on average slow down 1.8MPH more then smaller vehicles. Although, the mean speed of the larger vehicles over the whole distance was greater then the smaller vehicles, so the larger reduction of speed over the traffic calming measure compared to the smaller vehicles could be due to the difference in speed between the two different types of vehicles at the 25metres from the traffic calming measure. I believe that this is the case, as generally smaller vehicles travel at lower speeds and as a result do not need to reduce the vehicles speed as dramatically as larger vehicles.
Evaluation.
Throughout our data collection, I believe we did this to the best of our ability but feel that a number of factors may have altered the results we collected on the day and consequently, meant that the results collected may be inaccurate.
Firstly, as the weather that day was fairly overcast and rainy, there was a lot of surface water on the roads. As a result of this hazard, I believe that drivers may have been traveling at a lower speed than what the do usually, which subsequently meant that their speed over the traffic calming measure was different. Cars were also parked on the roadside both before and after the traffic calming measure, which subsequently meant that drivers had impaired vision over the course and had to reduce their speeds accordingly. As a result, drivers would have been taking more care when driving, as their reaction times would have been affected.
However, we also used another method of data collection to collect the information. We used stop clock to measure the time taken for the car to pass the traffic calming measure but I have decided against using the results in my project as I do not believe they give the most accurate of readings due to factors as a result of human error, which could have altered the readings. Other factors include the stop clocks not functioning correctly and people forgetting to start them, and thus making up times. In my opinion, the speed gun results give more accurate results. As a result, this would have affected my aims meaning them being incorrect.
If I were to conduct this investigation again, I would change a number of factors. Firstly, I would use a different method to collect the data. This would probably involve placing a series of electronic sensors along the roadside. By doing this, I would get exact speeds and timings of vehicles passing through the measure, so no human error would pay a major role meaning results would be far more accurate. Also, I would increase the number of vehicles surveyed and also make sure that I’d record at least five different types of vehicles passing through the measure. In doing so, this would make my investigation fairer. Finally, I would change the roads surveyed, which would be straighter with no fixed variables affecting the course. In doing so, we would get more accurate readings, as well as making sure that it was a clear day with no surface water on the roads.
Finally, I believe that my hypothesis I predicted was correct, as I feel that the results I collected state that the sleeping policemen have a far greater impact on vehicles compared to road cushions, as well as proving that sleeping policemen are more effective at slowing down the larger vehicles than the smaller ones.