Speeding is one of the main causes of traffic crash fatalities. Different effective strategies have been applied to prevent this critical issue; for example, humps, setting speed limit, and speed cameras. This study evaluates the effectiveness of speed cameras that are implemented on midblock of urban, suburban and on segments of rural arterials in Jordan in January 2018. Interrupted time series analysis (ARIMA model) was used for examining the effects of the speed cameras on the number of crashes. Various functions; including linear, quadratic, logarithmic, exponential, and power, were applied in order to evaluate the effect of speed cameras on traffic crashes. Results of analyses indicated that speed cameras implemented on suburban and urban arterials with speed limit less than 80 km/h had a crash reduction of 10 to 19%. On the contrary, it was found that the number of crashes on a limited number of rural arterials’ segments was increased by about 36%, this result should be further investigated since the sample size of rural segments was relatively small.