Can those traffic cameras be trusted?
Our fascination with vehicle speed and its measurement dates back more than a century
The WITBANK NEWS has been reporting on the speeding cameras in eMalahleni since July of 2018; with articles asking questions pertaining to calibration, suspicious fines and the compliance with the Guidelines for Speed Measuring Equipment and Traffic Light Violation Monitoring Equipment.
Our fascination with vehicle speed and its measurement dates back more than a century.
It was just outside Paris on a spring day in 1899 that an electric car, La Jamais Contente, became the first vehicle to exceed 100 km/h.
Speedometers have been standard equipment in motor cars since the early 1900s, and in the last ten years the widespread commercialization of global positioning systems (GPS) has provided us an alternative way of measuring speed.
A GPS is a positional speedometer. It will show your speed based on the average distance you’ve covered in the last few seconds, with adjustments for the Doppler shift from the range signals from the satellite constellation.
Khalid A. Al-Gaadi published an article titled, ‘Testing the Accuracy of Autonomous GPS in Ground Speed Measurement,’ in the Journal of Applied Sciences in which, through scientific enquiry, he stated that he had found that GPS ground speed measurement was, on average, accurate to within 1.27 km/h of the actual speed – making GPS ground speed readings more reliable than the readings your vehicle’s speedometer gives.
A resident of eMalahleni was shocked to receive a speeding fine, he was certain he hadn’t been driving the speed which he had been accused of driving.
Still sceptical about the trustworthiness of the fine he had received, he decided to check his dashcam (with built in Global Positioning System) – and was shocked at what he found.
According to the resident’s R500 fine, he had been driving 134km/h on the N4, whilst his GPS ground speed reading on his dashcam for the same exact date and time show that he had been travelling at 122km/h – hardly the 14km/h-over-the-speed-limit fine he had received.
The municipality has been approached for comment but had not responded by the time of this article going to print.
