Although there are several shapes and colors of road hump markings used around the world, there is no unified international standard for road hump markings. Road humps are causing a huge number of accidents and severe damage to cars in Riyadh, Saudi Arabia. This paper evaluates road humps in Riyadh in terms of detectability of road hump markings. The paper describes two experiments; the first experiment involves selecting the most three detectable shapes of road hump markings among six different shapes based on preferences of participants. The second experiment involves selecting the best combination of colors (White or Yellow) for the selected road hump marking shapes based on response time. The result of the second experiment was that the yellow colored road hump showed a faster response time compared to the white colored one. Regarding the shapes of road hump markings, the three shapes showed a similar response time as well as similar accuracies. These results suggest that color is a more important consideration than the type of shape when designing a road hump.