The authorities have recently installed a speed-beaker made of some compacted, hard material that can be screwed on to the road with nuts and bolts on the main Murree Road near the Ojhri Camp, Rawalpindi. Besides causing an inordinate shock to the chassis of travelling vehicles, this could also cause severe injury to backbone of passengers even if a vehicle crosses it at normal speed. I suggest the concerned authorities should remove this clunky obstruction and replace it with a proper speed-breaker built with coal tar and concrete near the Zero Point Bridge on the main highway. -KHALID MUSTAFA, Islamabad, via e-mail, August 20.