Double white lines, a slow cyclist and a tailgater
It is 8.15 am on a weekday. You are driving a saloon along a two-lane suburban road that has continuous double white lines painted down the centre for the next 300 m. Ahead of you, a cyclist is travelling in your lane at about 15 km/h. There is a steady stream of oncoming traffic on the other side of the road. Behind you, a van has been tailgating for the last 400 m, sitting roughly one car length off your bumper. You are doing 40 km/h on a dry road and visibility is good. The next junction is 250 m ahead and there is a slip road there where you could turn off.
1. A gap opens in the oncoming traffic and you can see 200 m of clear road ahead. May you cross the double white lines to overtake the cyclist? Explain your reasoning.
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No. A continuous double white line means neither side of the road may cross or straddle it at any time. The restriction is not conditional on visibility or on the length of the gap - 200 m of clear road does not turn a prohibited line into a permitted one.
Even setting the law aside, the manoeuvre is poor risk management:
- You would commit to the oncoming lane at 40 km/h while closing on traffic doing 50–60 km/h, so you need a gap long enough to overtake a 15 km/h cyclist and return to your own lane.
- The cyclist is unstable at low speed; a wobble while you are alongside puts him under a passing vehicle.
- You would be attempting it with a tailgater one car length behind, which removes any ability to abort.
Correct action: hold station behind the cyclist at a steady speed, leave a generous lateral gap (about 1.5 m) when you eventually pass, and wait for a broken line on your side with a clear view ahead.
2. How should you handle the tailgating van while you are stuck at 15 km/h?
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Do not react by speeding up to open a gap behind you, and do not brake-check the van. The van's driver controls the distance behind you; you control only what happens in front.
- Roll off the accelerator early and smoothly so your braking is progressive. A follower who is too close can usually cope with a gentle stop, but cannot react to a late hard one.
- Increase your own gap to the cyclist slightly beyond the normal two seconds, so you have a buffer to absorb a wobble without braking sharply.
- Be predictable: signal early and keep a constant speed rather than surging and slowing.
- If the van persists, take the slip road 250 m ahead and let it go past. That removes the hazard at the cost of a minute.
3. The cyclist suddenly swerves about a metre to the right, into your path, 20 m ahead. What do you do, and why should you not steer around him?
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At 40 km/h you cover about 11 m per second, so 20 m is under two seconds of travel. There is time to scrub speed, but not to negotiate a clean overtake.
Action: brake firmly in a straight line with the wheel held straight. Use the horn as a warning only - never as a substitute for braking.
Why not swerve: the only space to the right is the oncoming lane beyond a continuous double white line. A swerve there converts a low-speed impact with a cyclist into a head-on with oncoming traffic at a combined speed of 90 km/h or more. Swerving left takes you onto the verge or kerb; a kerb strike at 40 km/h will put you out of control.
If a collision becomes unavoidable, the least-bad outcome is a much slower impact in a straight line. Stop afterwards, switch on your hazard lights and give assistance.