Climbing lanes: Simple, helpful…but dangerously misused
Both climbing and overtaking lanes have a singular purpose: to ensure that slow vehicles do not obstruct the ambient flow when traffic is heavy in both directions and opportunities to overtake are limited.
What does the law say about using climbing lanes?
Not as simple as it should be or could be. Public information on the subject still muddles or omits the distinction between “climbing” lanes and “overtaking” lanes, and in Kenya, there is little evidence that the principles have been taught or tested. The default is, for better or for worse, “common sense”. All road rules and protocols should comply with that.
Both climbing and overtaking lanes have a singular purpose: to ensure that slow vehicles do not obstruct the ambient flow when traffic is heavy in both directions and opportunities to overtake are limited. The “third” lane enables that with a reasonable degree of efficiency and safety…if the principles are understood and followed.
Designs and rules vary among different countries, but the fundamentals are clear: There is a single carriageway carrying contraflow traffic. It has three lanes. The “climbing” lane is on the extreme left, going uphill. The “descending” lane is on the extreme left going downhill. In between them is the “overtaking” lane, which can be used by vehicles travelling in either direction when it is clear of oncoming traffic.
Vehicles travelling uphill have priority at all times. This is indicated by the road markings: the climbing and overtaking lanes are separated by a broken (dotted) yellow line. The descending lane is separated from them by a continuous (solid) yellow line.
Vehicles travelling uphill which cannot maintain the ambient speed of the traffic flow (which is supposed to be at or near the speed limit) should get into the climbing lane as soon as possible and stay in it. Faster vehicles going uphill should also use the climbing lane at all times, except when overtaking a slower vehicle. The overtaking lane should give them a considerable opportunity for doing so (that is its prime purpose). But once they have overtaken, they should return at once to the climbing lane; just as they would/should on a multi-lane dual carriageway until they need to overtake again. And so on throughout.
Most vehicles travelling downhill should be capable of maintaining an ambient flow speed at or near the speed limit and should stay in the descending lane as if it is a conveyor belt.
The point here is that although you might be going faster than the vehicle you are overtaking, there might be others going even faster who want to overtake you. There may also be vehicles coming downhill that want to use the overtaking lane, so do not block it unnecessarily. Failure to recognise and obey that is the most glaring fault and where the biggest dangers lie.
Most vehicles travelling downhill should be capable of maintaining an ambient flow speed at or near the speed limit and should stay in the descending lane as if it is a conveyor belt. However, some heavy trucks may have to descend at much lower speeds in low gears to use their engines as brakes (restraining them from becoming “runaways” by brakes only could seriously overheat the brakes and lead to complete brake failure). On very steep descents, the same applies to lighter vehicles.
There is a useful principle to govern this procedure: you should descend steep hills (especially if they are long or twisty) in the same gear that you would use to climb them. Do not “ride” the brakes.
Notwithstanding those factors, the point is that overtaking while going downhill is sometimes necessary and reasonable, and vehicles in the descending lane can use the central overtaking lane when it is safe to do so. That will mean crossing a solid yellow line, but that is not an offence if it is done with good reason, due care and safely. It is only an offence if done carelessly, recklessly or dangerously. The police themselves could be better taught and tested on that fact.
“Good reason” would include passing a vehicle that is obstructing the flow, either having broken down in the middle of the lane or travelling at much less than the ambient flow speed. “Due care” would require, above all, recognition that oncoming vehicles travelling up the hill have absolute priority.
“Safely” means judging that the overtaking lane is (and will remain) clear ahead for ample distance to complete the overtaking manoeuvre and return to the left of the solid line. That means judging not only what uphill traffic is already in the overtaking lane in the far distance ahead, but also whether faster vehicles currently in the climbing lane might be about to pull out into the overtaking lane. Once again the mantra of “common sense”.
Also read: Top 10 Kenyan deadliest highways
The problem is not that Kenyan motorists have less common sense than drivers elsewhere. The challenge is that we need more common sense than them because we have more slow trucks, more overloading, more old crocks and ditherers, more inexperienced drivers, more teaching and testing defects, more mixed traffic, more flibbertigibbet pedestrians and motorcyclists, more bumps and potholes, more anomalous designs and signage, and massively higher speed differentials in the same road space.
Many places with very much better safety records than us have much higher speed limits than us and just about everybody (all taught and stringently tested) drives at or near the limit (including the biggest trucks). But their arterial highways do not have mini motorcycles, tuks tuks, mkokoteni, herds of cattle, pedestrians, roadside (and sometimes road centre) merchants, and lines of nose-to-tail trucks lumbering at circa 40kph or less, and sometimes at such low speed it would be better described as “almost parking”.
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Clutch starting technique is useful but not essential
I am told that I should always depress the clutch before turning the start key. Is this necessary, and why?
When the engine starts, the first gear is engaged and the clutch is released smoothly to get the vehicle moving.
The formal procedure before starting an engine is for the gears to be in neutral and the hand brake to be fully applied. Depressing the clutch is mainly an additional safety measure (in case the car is mistakenly still in gear) so may be considered a good habit. It might also fractionally reduce the load on the starter motor.
Getting a static engine to spin fast enough to “fire up” takes a lot of power – to turn the weight of the flywheel and the crankshaft against the weight and compression resistance of the pistons and valve gear. A healthy battery and healthy starter motor have plenty of power to do that – indeed, they have enough power to briefly “drive” the car before the engine fires, which means also turning the transmission and the drive train against the weight (rolling resistance) of the whole vehicle.
If the gears are in neutral, the turning engine is disconnected from the transmission and drive train so these extra loads are not imposed. But the clutch itself will still be connected to the flywheel so the clutch mechanism’s own (minor) weight will still be part of the load the starter motor has to spin. A tiny bit more stress on the battery and the starter motor. Depressing the clutch before turning the key will lessen the burden by that small amount, which could be helpful if the battery is not strong.
When the engine starts, the first gear is engaged and the clutch is released smoothly to get the vehicle moving. Whether the clutch is depressed before cranking the engine or immediately after it has started makes almost no difference.
Consider the “reverse” physics of push-starting a vehicle without using the starter motor, either because the starter motor does not work and/or the battery is flat. The ignition is turned on, the gear is engaged (second gear is usually best), and the clutch is depressed. The vehicle is then pushed or towed to give it some momentum and when the car is moving at “jogging” speed the clutch is released. This engages the entire drive-train, and instead of the engine power turning the wheels it is the rotation of the wheels — powered by the moving weight of the vehicle — which turn the engine until it (hopefully) starts. The turning engine will spin the alternator and provide an electrical current to get the engine “sparking” and start to recharge the battery.
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Smoke signals from a troubled engine
I have a 1996 diesel 4.2 litres. It smokes a lot despite the injector pump and nozzle service. Initially, it spewed white-grey smoke, but now black smoke. Power increased after service, but I need the smoke out of the way. What should I do? Wafula N.
Grey exhaust smoke usually indicates that the engine oil is burning in the combustion chambers of the cylinders, usually because the pistons rings are worn or broken.
Grey exhaust smoke (diesel or petrol) usually indicates that the engine oil is burning in the combustion chambers of the cylinders, usually because the pistons rings (especially oil rings designed to stop oil on the cylinder walls being squeezed into the combustion chamber) are worn or broken.
White smoke (usually petrol) can indicate that the air:fuel mixture is too “lean” (lots of air, not enough fuel) so the combustion process is hyper-ventilated and too hot. A richer mixture is needed.
Black smoke indicates incomplete combustion of (usually diesel) fuel because the injector settings are too “rich”, either because the air filter is clogged or the combustion process is defective, usually because the compression is too low because the pistons rings are worn or the valves are not closing fully or forcefully enough (because of maladjustment, weak valve springs or lumpy carbon deposits stop them closing tightly enough).
Considering the age of your engine and reports of grey smoke, I suspect your piston rings are worn. At that time, your air-fuel mixture was possibly too “lean” (perhaps because the fuel pump was weak or the fuel injector nozzles were clogged). Since these problems were serviced, power improved because more fuel was being delivered. The black smoke suggests “too much more”. The settings need to be readjusted – preferably on a purpose-built test bench. That process will surely also check the condition of your air filter.
I would guess that the grey smoke (worn piston rings) has not disappeared, but has simply been obliterated by the dense black smoke. So, in addition to a test-bench re-set of the air: fuel balance of your injectors, have a compression test as a first check of piston-ring and valve-seal condition.
