Thursday 24 August 2017

One and and half car lengths

According to the Highway Code braking distance charts, the "average car" is 4 metres long. The stopping distance available in the allinson crash was 6.65m

Wait for a day when the road isn't wet and slippery

Find a flat, traffic free road,

Find two parked cars in a row. 

Not estate cars, or bloated SUVs, just what's left of what was "an everyday" car at the time the highway codet was written: an Astra, Focus, Civic, etc.

Go up the road from them, 50 m away

Get on your bike: one with a computer, accelerate to 18 mph and stay at that speed, pedalling at a cruising speed. 

As you approach that front car, brake. Hard. Can you stop before your front wheel reaches the end of that second car? Because that is what the guilty verdict in the Allison case turns on. 

Except: that's your stopping distance where you are anticipating the stop, where you know when to brake. Which is exactly what the police video shows they did

Now go online to a braking distance calculator:

Look at those numbers. 5m "braking distance" -that's in a car, where, as Martin Porter QC covers, can put a lot more braking force in. Your stopping distance in a bike is going to be worse, even with a lot less momentum to burn off.

What's alongside the actual braking distance? Thinking distance. 5 metres. Giving a total stopping distance of 10 metres. Two and a half car lengths.

Similarly, go the official Highway Code stopping chart, look at the closest numbers it has: 20 mph. Six metres for a car to stop, and equally critically, 6 metres of thinking distance.

You cannot correctly estimate the stopping distance in response to something happening in front of you without including that thinking time. Which is precisely why it is included in the Highway Code numbers. 

So why has it been left out here?

Charlie Allinson is the poster child of everything people hate about cyclists: a hate figure the press can vilify, that none of their readers can relate to. And the fuckwit took their front brake off. Which is used as the focal point of the prosecution, and the public condemntation of all cyclists today. 

If he had a front brake, would he have been able to stop in time? 

That is not a question the met office experiment answers, because it doesn't include that thinking time. 

So get out there, find that road, and measure your bikes stopping distance when you are anticipating coming to a halt. Then add five metres of thnking time. Is the total more than 6.65m? Or less? Because, if, our experience holds: there is no fucking way you can do it, even with a mountain bike in full emergency stop mode: disk brakes on hard, fat rear tyre locking up, rider pushing their arse out the back and low to keep that rear wheel weight up. Irrespective of bike, once thinking distance is added in, even that police experiment implies a collision was, sadly inevitable. The kind of crash where in a car or van, the "just came out of nowhere" defence would be wheeled out and the driver would walk out of court, as worse with a few hundred pounds fine from a guilty plea of "death by careless driving"

If a collision seems inevitable the, what did the lack of a front brake do?

it may have meant the rider was going faster when he hit Kim Briggs. A slower speed collision may have meant that her family wouldn't have got the worst news of their lives. It may also have given him some control in the crash: possibly even enough to steer around her 

But there is no way, front wheel or not, someone on a bike or car travelling at 18 mph can come to a unanticipated stop from in 6.65m. The sole defence there is for everyone, car or bike, to recognise when they don't have visibility, slow down and and be ready for someone stepping out. 

Which is something we all need to do: otherwise, it's us next in court, getting crucified by the press "they mowed her down". Or the far more frequent and equally tragic case, walking out of court with the "they came out of nowhere" defence working, nothing but a small mention in the local press -and a family left to mourn about the injustice of a road safety system where they can prosecute a cyclist for not stopping in under 7 metres, but let speeding drivers off with an apology "it wasn't your fault"

Sunday 18 June 2017

Summer driving tips: bends on country roads

Summer driving tips: bends on country roads

This is the time of year when leisure drivers go on leisure journeys on our roads, rather than restricting their hobby to motorways dedicated to it. These people are often unused to driving on country roads, and need to treated with caution. Often these people haven't yet learned their highway code -or worse, picked up third-hand misunderstanding of it from social media.

For leisure drivers, here is some advice to help them enjoy their hobby better, by driving safely with the users of the road who are trying to use it for work, important journeys such as to shops, and family duties.

"What do it I do if I come round a bend and find a cyclist in the middle of the lane?"

If you are asking this, you've already made the mistake. The question you should ask is: given there will be other road users on a British Road, how do I safely go round corners?

In a two lane road, you need to anticipate what could be behind the bend. Slow moving tractors, horses and cyclists heading the same direction and things to anticipate. You will implicitly be approaching them at a "closure speed" of the difference between their speed and yours. The faster you are going the, the more you endanger yourself -and, if it is a vulnerable road user, them. The secret here is to slow down for the bend, drop a gear to use the engine to help control yourself though the corner, and be prepared to break as soon as you see something in your lane. If, as you complete the turn, the road ahead is clear, you can accelerate out of it -as you will already be in a gear to do so. In a front wheel drive, this will straighten up the car's direction-so wait until the corner has been completed. Rear wheel drives will not straighten up this way, but you do still need to wait for visibility. The best cue here is actually the lines in the road centre: if the line on your side goes from solid to dashed, it means that visibility for a long distance is now considered adequate for overtaking, -time to speed up, if safe.

You also need to plan for something completely stationary in the road: a fallen tree, a crash, a broken down vehicle. Here the closure rate is even higher than for a horse or cyclist, so be prepared to brake fast.

The biggest risk in a two- lane road is coming round to find an oncoming vehicle heading towards you. Here the closure rate is your speed plus theirs, and any collision will be very destructive. This is a common problem when there are other leisure drivers on the roads, those without enough experience to have the judgment safe driving needs. These drivers may have overtaken a horse, tractor or car too late for safety. Motorbikes can be expected to do this too, especially on "classic" roads for their leisure rides, such as, near Bristol, the Wye Valley Road, and the Chepstow to Usk road followed by the A479 from Abergavenny to Mid Wales.

These overtaking cars and motorbikes are very dangerous because they are coming towards you so fast. Again, a controlled execution of the corner in a lower gear, holding onto the wheel (no texting here!) and being ready to switch from accelerator to brake pedal is the best way to prepare. Motorbikers will, if given a moment's chance, slide into the main traffic stream. Drivers who have misplanned an overtake are a different problem: there is often nowhere for them to go. These drivers often lack experience and react badly by trying to complete the overtake. Brake hard, don't be afraid to engage the ABS, and don't worry about the strange feeling you get though the brake pedal. This is the ABS at work. You can still steer the car at this point, so do try, while slowing down, to get the side of your lane. If the vehicle/bicycle/horse being overtaken brakes/slows down and move to the side, there may be room to avoid a head on collision. If such an incident happens, if you have a dashcam, send the video to the police. Someone else may have a video you could use as evidence too: search for your registration number on youtube to see.

If this all seems scary -don't panic! With practice and experience it will become easy. The key things are the "two-A's": attention and anticipation. If you look ahead, and anticipate the horse, the cyclist, the fallen tree -then every time you encounter this you are ready. And when you don't? Time to accelerate out the corner, getting to a safe speed for the next bit of road. Of course, if there is another bend, you should just stay at the current speed and plan the next corner.

Looking at other vehicles is often informative too: if there is a vehicle in front, as you enter the corner, give it room to manoeuvre and brake, and look at its lights as a cue for braking yourself. If it's brakes come on, brake hard yourself, ready for what is ahead. It may just be they underestimated the size of the bend, and didn't approach it at the right speed. Just as easily, they may lack the experience to anticipate what is round the bend, and are now reacting badly.

Evening/night driving.
Although these situations give you a good cue that a car is coming: headlights, the loss of visibility makes it harder to estimate how sharp a corner is. Assume it is tight and approach at a speed which you can sustain through a longer bend. If you are driving with headlights at full beam, drop the, before you enter the bend. This has multiple benefits

  • If there is an oncoming vehicle, they aren't blinded as you come round the corner
  • It can give you more warning of an oncoming vehicle, because their lights will now light up the bend better
  • Finding and using the dipper is one less thing to worry about if you do come round the bend and encounter an oncoming vehicle, so you can hold onto the wheel and complete the turn.
A key hazard is if an oncoming vehicle is driven by someone inexperienced, one who has not pre-emptively dipped their headlamps. As you come round the corner, there is a risk that their beams briefly interfere with your vision. Again, anticipating this avoids any surprise. If you see any vehicle lights after you dip your lights, unless you see any signs of them dipping their beams, be prepared. What to do? Don't t look at the lights: look to the dark bit to the left, where you need to go. You will automatically steer in that direction. At the same time, you need to anticipate other road problems, so slow down until you can see ahead. There may be someone on a bike: look for the red read right or reflector. It may also be a terrain feature, such as a continuation of the bend. Use the white lines by the sides of the lanes as as a guide. A big hazard here is the Z-bend: before accelerating out the bend look ahead for warning signs of a subsequent bend. And of course, any Z-bend warning signs before the first one -but remember there may be more than two!

Dusk and dawn need special call out as dangerous. Why? Animals, especially deer. Dusk is when they come out and start foraging. Be particularly cautious near woods, especially if there are deep woods on either side of the road: a deer can easily jump out without warning. Again, for corners, anticipate them. Important: unlike sheep, a deer by the side of the road may well jump out in front of you. If you see a deer by the road-side, brake hard immediately.

If you are following another vehicle at night, and you are in an area you recognise as hazardous, increase the distance between you and the car in front -this gives you more time to react. Otherwise: attention and anticipation will again, get you home.

You also need to consider low sun at these times. It is straightforward to predict this: if the sun is low, and you are turning in its direction, at some point in the turn the sun will be in your eyes. Anticipate it, so you aren't surprised, and plan for the risk that there is a slow moving vehicle/horse, bicycle, deer or pedestrian you will need to avoid. Braking as you turn, before the sun hits your retinas, prepares you for such events.

Driving on country roads, especially at night, is often one of the driving skills hard to learn. It's not just that it is never taught or tested when learning to drive, it is so unlike urban driving. Who sees a deer in town? Or comes round a bend to discover some pedestrians walking on your side of the road-as recommend in the Highway Code? Practice will help-but beware of overconfidence.

What to do if this is all too much?

If you find this intimidating, and don't think you can safely drive round bends on country roads, in day or night, stick to motorways. These provide a low risk driving experience where bends are gentle, and separated lanes means that you will not encounter oncoming vehicles; segregation will keep you safely away from pedestrians, cyclists and tractors. You do still need to worry about deer: take care at dusk.

Saturday 25 February 2017

Nobody should be buying a new diesel car

Apparently in January there was a 4% drop in the sales of new diesel cars.

This might seem a good thing, and while it's a start, it's not much of one. What you may be seeing is a change in purchasing decisions by those people who care about urban pollution —in a month when the NOx pollution in cities was at such a level that it got lots of press.

What that is not evidence of is something more significant: a decision by the majority of new car owners to opt for petrol cars. And why would they, when the cost of Diesel fuel is little different from that of petrol, you get better mileage, and there's no penalty for opting for diesel? Especially as all the manufacturers are saying "EURO6 diesel is clean", meaning "ignore dieselgate and the fact we have until 2021 until cars actually meet the real world EURO6 tests". While the term "conspiracy" is usually a bad sign, here we are seeing the car manufactures of key countries in Europe: Germany, the UK, France, Spain(?), pushing hard for diesel against hybrid/e-car alternatives, their governments setting the EU standards. There's a big reason that US diesel limits are so much tighter than EU ones: the car industry there hasn't embraced diesel, isn't committed to it, and so hasn't been pushing for relaxation.

Here though: the car manufacturers like diesel engines, customer sare happy to buy new diesel cars, and the governments have been going along with it. Take for example the UK being taken to court over NOx pollution. The entire policy of the government has been one of believing that EURO6 will fix things. They too fell for the lies, and we are suffering for it.

Last week, the 2016 used car sales figures were announced, showing a "healthy" market. Diesel cales increased 11.1% and petrol transactions grew 4.7% compared to 2015.

Does that mean that second hand car customers all decided that they wanted to buy diesel cars? No: it was documenting the harsh truth: you don't get a fucking choice. For many types of car, petrol models are rare on the ground. Estate cars, MPVs: mostly diesel. The choices of engine you get three year are really the choices made by others in 2013. EURO5 diesel it is. Sell your car threes later and in 2019, people down the food chain, again, diesel is what they get.

The longevity of modern cars means that diesel will continue to pollute our cities even if sales of new cars diesel engines were banned tomorrow.

That's what the "Scrap a diesel" program admits. It admits that the cars built 15 years ago are out there, and rather than have any form of restriction on their use, they "may" even reward drivers.

Except wasn't there a car scrap scheme a decade ago? Yes there was, in 2008. Wasn't it meant to reduce pollution by getting dirty cars off the road. Was is meant to reduce pollution, yes it was. At the time according to Paul Everitt,, SMMT CEO said:
CO2 isn't the only evil being scrubbed out. "There are other tailpipe emissions to take into account," Everitt says. "We're going to see the benefits of these extra new cars affect road accident statistics and the health of us all for years."

Well, times moved on. We aren't seeing those health improvements: urban NOx pollution has got worse. And now, in 2017, the SMMT are back cap-in-hand, saying "this time a scrappage scheme will work".

Another scheme may work for the SMMT, but it scrappage scheme won't deliver, any more than the first one did.
  1. It's voluntary. People with aged, dirty diesels who don't care to upgrade can carry on as before. Which means some of the worst polluting vehicles will do nothing.
  2. It's not focused on those vehicles which do the most miles in inner cities, so cause the most pollution: taxis, delivery vans.
  3. A 1:1 replacement scheme will mean the congestion situation will be no better, so continuing the cause of much of the pollution.
  4. It will take a long time for any possible benefit to surface.
  5. It will reward the people who keep the older diesels around —and in doing so punish those people who bought petrol cars.
  6. It takes away money which could actually do something, today.
#5 is key: if we are to have a "pollution cutting" scrapping scheme every ten years, then you may as well buy another diesel, expecting that another decade from now, the country will again give you a discount for getting a new one. Todays "clean" EURO6 diesel cars will be come 2028's "dirty" diesels.

And they buyers of second hard cars? Along with getting no choice, if you buy older cars, well, why not get a 2017 diesel in 2024, expecting a discount on replacing it you wouldn't get if you;;d bought the rarer 2017 petrol models?

There is a better way. Abandon the carrot, point out the stick on the horizon, and bring it out on emergencies today.

Imagine if the government worked with a set of cities to set a timetable, today, for a ban on EURO5 diesels by 2020, EURO6 by 2024, charges for petrol cars higher than those of electric and hybrids. It may seem a long way off, but what it says for today's purchasers of new cars, "petrol cars will be worth more when you sell them"

Because that does matter, today: the perceived depreciation of the cars you buy. If, after ten years, a diesel car is unusable in town, its going to depreciate far more than a petrol one. That changes the running costs, as unless you drive lots and lots of motorway miles a year, getting the most of the MPG difference, a diesel car will cost you more per year.

And before that scheduled ban is rolled out, the government can give cities the right to roll out emergency diesel bans, which will block all diesel cars on "critical days". The standard for those could be kept high —what matters is their very existence and intermittent use. Every day one happens, it highlights how big a problem NOx pollution is, how much traffic is to blame, and again, scares people off buying diesel cars —new and second hand.

Returning to those second hand diesel sales: the ratio of petrol:diesel is meaningless, all it reflects is new car sales 3+ year ago. What is informative will be selling price —whether or not diesel cars depreciate faster. As every sign that diesels depreciate faster is another sign to new car buyers that diesel isn't a cost saving —its a financial mistake.