Safety is one of the key functional factors of a road network and is especially incorporated in the design of highway geometry. Road designs should not only ensure safe vehicular operations such as providing sufficient visibility and skid resistance, roadway characteristics should make provisions to reduce the severity and probability of road crashes. Road signs, road markings, signal lights, etc., are installed to ensure provision of necessary guidance to the drivers to operate their vehicles in a safe manner. Road furniture, such as median barriers, ensures that the severity of crashes is minimized. Similarly, installation of rumble strips along the roadway edge has been proven as an effective countermeasure against run-off-road crashes on highways. The vibration and the noise generated when the tyre traverses over the rumble strips act as an alert to the drivers to help them manoeuvre the vehicle back to the lane safely. This study aims to explore various rumble strip designs and arrangements to identify an optimal design which would provide sufficient noise level while being cost effective so that it could be implemented on expressways in Sri Lanka.