Do You Think You're A Good Driver?

[Never had any say Panda]

Firstly I’m writing this in response to the Reality Check conversation. I’m not targeting anyone in particular, P-Platers, Old People and Mid Life Crisis’ers are all just as likely to die on the road. I’m yet to see a statistic that takes into account average time spent driving. P-Platers may seem to die more but they do tend to spend alot more time on the road compared to the elderly people who may leave the house once or twice a week.

Every time you get behind the wheel of a car you have a Duty of Care to every other person on the road. Pedestrian, Cyclist or Driver alike.

In the Reality Check forum a few people were very quick to blame young people.. ‘Watch out these cars are getting cheaper now’. As I said above.. Show me a statistic that compares average amount of time spent driving in a week to mortality rates. These accidents can happen to anyone and truthfully sometimes there is nobody to blame.

Many people don’t know me but I spend my days designing road upgrades and doing crash analysis and investigation. What I’m hoping to achieve is a little bit of a wider awareness of things that can cause very serious accidents (especially if you’re dicking around).

Okay firstly alot of this stuff is from the more rural settings where people seem to think they can go faster even though the roads standards are generally sh*thouse.

There are alot of other potential topics that may include Drive Awareness, Knowledge of the Road and General Skill but there isn't really anything that needs explaining in those. I'm not going to sit here and claim that every person should be made attend Defensive Driver Training.. Personally I'd rather see people getting a chance to practice on a well-weathered skid pan to get a sense of vehicle recovery tactics over doing straight line braking from 80km/h.

I hope there is some new information in here for people. These are just my observations and not to be taken as gospel.

SPEED

It’s the obvious killer isn’t it? The cause of all accidents apparently if you believe all the hype. I seriously don’t give a sh*t about vehicles who want to speed. Just watch it when you’re approaching intersections and curves and around traffic. People pick gaps in traffic based on an assumption of distance and speed of the vehicles on the road they are turning onto. So at 110km/h you’re covering 30.6m/s, imagine if one day you’re giving it the old lead boot and someone picks a gap in front of you? Ridiculous speeds really make it hard for people to pick gaps cause they are going to make their move into the traffic lane at the assumption you’re travelling at a normal speed. The funny part here? Legally they don’t even have to be doing the speed limit, they just have to be established in the traffic lane and if you run up their arse you’re at fault. Also not to mention the risks involved if you attempt to dodge them. (See the section on Tree’s further down)

Also just briefly on Advisory speed signs (The yellow plates bolted underneath diamond warning signs) they are there for a reason. Admittedly they are giving the advisory speed for to satisfy a ‘comfort’ criteria for negotiating the obstacle. They are only put there when there is actually a reason for them. I had the pleasure of briefly knowing someone who thought any advisory speed sign could be doubled while driving the blackbutt range. I know some are ridiculous especially when they say 90 and you’re in a 100km/h zone. But pay attention when they start saying 70 or lower..

OVERTAKING

No overtaking lane? Don’t worry there is a dashed line. It’s safe!.. NOT ALWAYS! Generally yes but all these areas are sighted based on a standard car and alot of them sighted based on a standard car in the 60’s. Ride heights have dramatically lowered since then (1.15m driver eye height to the current 1.05m driver eye height)and it may not seem like that drastic of a difference but when you’re trying to look 300m+ down the road to pick a suitable gap you are talking a fair difference in available sight distance (30 or so metres).

Another thing that alot of people don’t take into account is slipstream. When you are travelling behind a vehicle the work required by your car is significantly less. Many people don’t realise that pulling out to overtake a car you are effectively hitting a wall of solid air. If you’re unsure about an overtaking opportunity make sure you’ve got at least enough visibility to begin to accelerate while still in your current lane.

So when you’re sure of the opportunity to overtake many people also aren’t aware that the centreline of the road is actually the highest point of the road formation. It’s not flat. As you cross over this line the car is effectively crossing a 6-10% algebraic grade change (a bump basically). If your car has a very rigid suspension setup it is quite common to lift a back wheel while crossing the line. Combine a lifted back tire, LSD and WOT. With the wrong person behind the wheel it’s a recipe for disaster.

ROADSIDE VERGE

It’s quite common in areas where roads have an Asphalt overlay for there to be a significant edge drop off as very rarely is the edge of asphalt profiled after laying. With a bit of water this will wash out very easily. These drop offs appear deceptively small but are quite often 15-25cm deep. In the 60’s this wouldn’t be a problem but in the modern day with lowers cars and more rigid suspension it can and will rip a tire from a rim. Most drivers panic when their tire goes off the edge and attempt to correct by applying the brake and steering. Having two wheels on gravel, dropping the weight on the nose of the car and trying to force the front wheel up a rough lip of asphalt will rip a low profile tire from the rim very easily (plus buckle the rim). I’ve seen too many areas where this has been the cause of someone hitting a tree. Best advice when this happens if it’s clear, brake slowly, reduce your speed, negotiate back onto the road then accelerate. If it’s not clear, continue along if possible until you notice a much flatter area you can bring the car back onto the pavement.

TREES

These things are fun. Far too common next to roads but there are a whole bunch of hoops people have to jump through to provide any significant clearing. Ideally at 100km/h at least 10 – 15m out from the edge line should be perfectly clear. Tree’s aren’t really a hazard unless you’re unfortunate enough to go off the road. But as a rule of thumb if the trees in the area are thicker than your forearm (4" for those skinny armed people) they can kill you if you hit them. So if you’re looking for a spot to dick around don’t do it when there are trees around. A potentially minor accident can become a fatality with the addition of those bastards.

SEAL BLEEDING

This is where you notice areas of bitumen seal that don’t appear to have any stone spread across the top of them. It’s effectively where the stones has been pushed deeper into the seal then it should and requires water blasting to rejuvenate the surface (Not cheap). In the dry conditions this isn’t really a problem but it only take a small amount of water or oil on the pavement and no matter the condition of your tires you will lose almost all grip under that wheel. Combine this with turning or heavy acceleration.. Go figure..

RUTTING

As the name suggests these are generally very shallow Ruts in the road that run parallel to the centre line. Generally caused by heavy vehicles fatiguing the road pavement. Nothing wrong with these normally but add a bit of water and all bets are off.. Generally road surfacing texture is ideal to allow the water to run off while still making contact with the tires.. In rutted roads this won’t happen. The deepest water level is actually in the wheel paths. If it’s pissing rain use your head and shift over closer to the edge line. Just get your tires out of the deeper water.

AQUAPLANING

So from reading a couple viral emails about cruise control and water on the road I have no idea how true that is. But regardless of cruise control or not aquaplaning is a very serious thing. There is a huge difference between full aquaplaning (very rare) and partial aquaplaning (also aqua-skidding) which is common. 99% of the time it is one or both front wheels losing contact with the road surface. Full aquaplaning requires all 4 wheels to lose contact. Commonly enough most people freak out and fight the steering immediately when they feel the aqua skid start. Easiest solution just very lightly tap the brake. Shifts the weight back onto your front tires. Over apply the brake and you can make it worse. Combining over steering and over braking in an attempt to correct this will go very wrong. In order for your brakes to be highly effective on a very wet surface you have to generate enough heat between the tire and the road surface to evaporate residual water.

ROADSIDE SLOPES (BATTER SLOPES)

Okay so we are only interested in the fill slopes. Roads through cuttings well the hazard is smacking into a damn wall of rock.. In a fill situation it is incredibly hard to judge the severity of the slope just by looking at it while driving past. Generally roadside slopes should be ideally 1m(V):6m(H) (Think triangles 1m down for 6m across. Also referred to as a 1 on 6 fill). I have never yet encountered a new project that utilises the 1 on 6 slope. Reason being it is incredibly expensive, has a much larger footprint. Mostly road authorities are attempting to use a 1 on 4 slope (25% slope) as this is considered ‘recoverable’ to a car with a low centre of gravity (Sorry to the fourbies). Slopes between 1 on 3 and 1 on 4 are ‘traversable’ to a car with a low centre of gravity, which means you should be able to drive safely to the bottom. Slopes steeper than 1 on 3, you are quite literally screwed.

When this refers to low centre of gravity remember it is referring to an average centre of gravity.. If your car is lowered and you end up in this situation you’ll most likely dig your front bar into the dirt then all hell breaks loose.

ROAD GEOMETRY

Simply put the horizontal and vertical alignments of a road combined to give you a singular geometric grade line. In a perfect world all crests would be so flat you could see right over the top of them and all horizontal curves would be perfectly up to standard with the correct application of superelevation suited to the curvature. WRONG.

Road geometry is dictated by so many constraints (some blatantly stupid things also) that it isn’t always perfect. It’s actually damn hard to get something ‘perfect’. These days we are re-aligning roads around certain clusters of trees just to keep the EPA happy (See they aren’t just annoying about emissions). When you turn into a curve on a road it is effectively a multi stepped process.

1. You commence the turn onto a larger radius spiral.

2. The crossfall of the pavement begins to rotate to increase the available side friction (This is superelevation).

3. You turn onto the main curve (Enjoying the fact that you can keep doing the speed you were doing as the superelevation is fully developed)

4. Crossfall starts to rotate back to normal.

5. You complete the turn by going around yet another large radius spiral.

Not every curve on the road is transitioned as mentioned above and 90% of the time you can’t even pick it is.

So if roads are designed to keep us stuck on at curves, what goes wrong?

As mentioned above sometimes we have constraints to designs and while everything must be built according to sound ‘engineering judgement’ that only takes into account the average 85% of drivers. The top 15% are on their own.

I may only be 25 but I’m getting sick of staring down accident histories and then walking around roadsides trying to find what the hell went wrong, knowing that someone died here. It’s a damned shame that it happens so much.

The best advice I can offer anyone driving on the roads is to realise that if you go and do something stupid you can’t blame the road. There could possibly be over a hundred different factors involved with any crash on the roads and we’ll never know them all. It’s not about knowing your cars limits, it’s about knowing your limits as a driver!. Some (very few) people can actually say that they can take a car to its limit on the racetrack. Flame all you want but no one can say that on the road they have exceeded the limits of the car. Know your own limits as a driver, remember that it’s not just your own safety it’s the fact that your car can and will kill other people, drive to the conditions (not the posted speed) and for Gods sake!!! Please stop writing off our beloved XR6T’s!!!

[WILD_XR]

A very enjoyable read. Great post.

Complacency is a big issue.

[Buf-Phoon]

what an enlightening post , well done champ

Just confirms to me that most drivers need to truly understand the limits of the vehicle,

driver , as opposed to ambition.

Always drive to the conditions and keep it all soft hands and smooth, just like a woman really

That said there are always situations that warrant a spirited approach ( women)

See so many people making severe vehicle applications , steering , speed, and braking in adverse

conditions and wonder why they spear off the road

[j.d]

Good write up!! I was glued till the end !

[STAINLESS again plz]

Smokos over. Back to work.

[senna_T]

Well Done for posting this - something everyone and anyone should read and understand.

[mercuryturbo]

Very nice write up mate. Make it a sticky mods.

[CBXRT]

Good stuff mate,

I haven't had a crash in 14 years of driving (and always owned fast cars), and yet a few weeks ago when simply turning right, my T suddenly spun sideways and threw me off the road.

I wasn't speeding or driving recklessly, so I can only assume it was oil and/or maybe black ice, completely shocked me. Accidents can happen when you least expect it, and road conditions are not always visible - which certainly don't combine well with heavy rear-wheel drive cars.

If I had been going faster it could have been much worse, and plenty of people don't get a second chance.

Cheers.

[Dillz]

  On 16/09/2011 at 1:48 AM, mercuryturbo said:

Very nice write up mate. Make it a sticky mods.

[tab]

Good write-up but it sh*ts me that it comes back to road design. A continuation of the nanny state wrap-them-in-cotton-wool mentality that seems to be becoming more prevalent.

Teach people how to properly control a vehicle in all scenarios (including rural roads etc.), give a license only to those that genuinely deserve it and can manage to engage their brain, and the rest isn't really relevant.