Red light violation by motorcyclists is common in Indonesia. Therefore a study on this behaviour is essential. Observations were made on an intersection approach in Jakarta on 4 hourly observations at 5.00, 8.00, 12.00 and 15.00. Two types of violation were found, (1) at the beginning of red and (2) at the end of red. The type 1 was dominant during the early morning observation, whilst type 2 was dominant during the other three observations. The analysis shows that the higher the degree of saturations (Q/C) the higher the rate of type 1 violation and the lower the Q/C the higher the rate of the type 2 violation. Higher Q/C encourages motorcyclists to wait their turn in front of stop line and using gaps during the inter-greens. Lower Q/C allows a higher speed thus enables the use of the amber time or even all red time to cross the intersection.
