in recent years black deposits have appeared on heavily trafficked sections of motorways in dry weather. these reduce the resistance to skidding at both low and high speeds, and cause pollution to streams after subsequent rain . the deposits are formed from oil dropped from the automatic chassis lubrication systems on heavy vehicles and from rubber abraded from tyres. research is in progress to study the formation of deposit and the extent of the pollution problem, and to determine what practical means there are for preventing the build-up of these deposits; experimental surfacings and cores have been laid on motorway m1 as part of this work. remedial action has not so far proved very effective and measures to prevent the deposition will almost certainly be needed in the future. (a ).

Want to know more about this project?