A dual carriageway is a multi-lane road, with two or three lanes, having a central reservation usually of grass verge in the centre of the road with or without crash barrier separating streams of traffic travelling in opposite directions.
On a dual carriageway, you should normally drive in right-hand lane; use the left-hand lane for overtaking or turning left. If there are slower vehicles in the right lane, after overtaking, you should return to the right lane when you have passed them.
On dual carriageways, the average speed is higher than many other roads, and we encounter pedestrians, motorcyclists, tricycles (Keke), parked vehicles, entrances to building, etc. When driving on dual carriageways you should use your mirrors even more frequently. Look well ahead for problems, and anticipate what may happen.
You may join a dual carriageway in three ways. Your road may simply turn into a dual carriageway ahead; from a slip road; and emerge directly onto a dual carriageway from a T-junction or crossroad.
Driving along dual carriageways
After you have joined the carriageway check your mirrors; cancel your signal; keep in the right lane; and make good progress. When driving on dual carriageways you should use your mirrors even more frequently. Respond early to other traffic, by giving those behind you time to act. Look out for obstructions in your lane; vehicles ahead slowing down; vehicles turning through central reservation; and traffic joining the carriageway.
Emerging directly onto dual carriageway
To turn right
Where there is no slip road you would need to emerge as you would to turn right onto a major road. Take into account the speed limit on the dual carriageway to help judge a safe gap as traffic may be approaching very fast
To turn left
When joining a dual carriageway to take a left turn you will need to cross the first carriageway before you can join the carriageway you want. This is easiest where the central reservation is wide enough to have room to protect the full length of your vehicle to enable you to emerge from one carriageway at a time. Where there is not enough room you would need to be extra careful and turn left when both carriageways have a safe enough gap for you to drive across safely.
Making progress on the dual carriageway
When on a dual carriageway, if the road is clear and the weather conditions are good then maintain an appropriate speed. Keep a safe following distance by applying the two second rule: – “Only a fool would break the two second rule”. To make good progress you should overtake slow moving traffic when you are sure you can do so safely.
In next week’s article we shall be discussing how to safely deal with expressways using the hazard routine. For further explanations or clarification on the articles in the Essential Skills of Driving column, consult the author.
Stephen K. Dieseruvwe
Director General, Delta State Traffic Management Authority (DESTMA)
**Driver Trainer and Road Safety Consultant