Four-way stop, a tailgating taxi and a diesel-slick stop line
At 17:35 on a wet Tuesday you ride a 125 cc commuter motorcycle westbound in a 60 km/h suburban zone. Rain has just stopped and a thin diesel sheen lies on the tar at the stop line of the four-way intersection where Protea Road meets Tenth Avenue. Three vehicles arrive within about a second of each other: a hatchback from the north, on your right, with its front wheels already across the painted line; a bakkie from the south, on your left, indicator ticking for a right turn across your path; and you from the east. Behind you a minibus taxi flashes its headlights and creeps to within roughly two metres of your rear wheel, closing the 1,5 m of space you had deliberately left. Your visor is fogging at the edges, your gloves are wet, and a crosswind pushes you towards the centre of the lane. You intend to continue straight through the intersection.
1. State the order in which the three vehicles should proceed and explain the rule you applied to each pair.
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Order: hatchback first, then you, then the bakkie.
- Hatchback vs you. At a four-way stop the vehicle that stops first has the right to move off first. Where vehicles arrive at effectively the same moment, the general intersection rule applies: you yield to traffic approaching from your right. The hatchback is on your right and its wheels are already across the line, so it has both the arrival and the right-hand claim. It goes.
- Bakkie vs you. The bakkie is on your left, so it must yield to you. It is also turning right across your path, which means it has to cross your line of travel and must wait until that line is clear. It does not go before you just because it is bigger or indicating.
- Bakkie vs hatchback. Once the hatchback moves, the bakkie still cannot turn right until the hatchback has cleared the junction, because the turn crosses the hatchback's path too.
So you move second, after the hatchback has clearly committed and the junction is clear. You still confirm the bakkie's wheels are stationary before you pull away - an indicator is a request, not a permission.
2. The taxi is pressing you. Describe what you do in the last 30 metres before the stop line and explain why, including where you place the bike.
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Plan the stop early and leave yourself an escape route.
- Start slowing at about 30 m, not at the line. Roll off the throttle and use engine braking plus gentle, progressive pressure on both brakes. A late, hard stop on a diesel-contaminated line is how a rear wheel steps out and how the taxi behind you gets no warning.
- Flash the brake light before you actually need to slow hard. A light touch of the rear brake lever brings the brake light on early and signals the taxi driver you are decelerating.
- Choose a clean patch of tar to stop on, not the sheen. Stop 1,5–2 m short of the line so you have forward room if the taxi does not stop, and pick the strip where the surface looks dry rather than rainbow-coloured.
- Position slightly to one side of the lane. Sit towards the left-hand side of your lane so that if the taxi locks up you can move forward and to the right into the gap rather than being pinned against the kerb.
- Stay in first gear, clutch in, right foot on clean tar, front brake covered. Watch the mirrors until at least two vehicles behind you have stopped. Only then relax.
Do not brake suddenly at the line, and do not wave the taxi past - a hand signal is easily misread.
3. How does the diesel sheen change your braking and your foot placement at the line?
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Diesel is a friction problem, so everything gets earlier and softer.
- Braking: the front brake does most of the work on dry tar, but on a slick the front tyre is the first thing to lose grip. Apply both brakes lighter and earlier, with a long, smooth build-up instead of a squeeze at the last moment. If the front starts to chatter or the bars twitch, ease off the lever rather than grabbing more.
- Bike attitude: keep the machine upright and the bars straight while you brake on the contaminated patch. Braking while leaned reduces the grip available for the tyre's side load.
- Foot placement: put your foot down on the clean, dry part of the tar - often the centre of the lane where tyres have polished it dry - not in the rainbow patch or on the painted line, both of which are slippery when wet.
- Expect the unexpected: if the front does lock, release the lever immediately and let the wheel roll again; a locked front on a 125 cc bike goes down almost instantly.
If you can avoid stopping on the sheen altogether by stopping a metre earlier on dry tar, do that instead.