Safe Speed / Hesitation

[foxtrot_mike]

Sorry to keep asking all these questions but they these are causing me a few problems.

Does anyone have any advice to offer me on how to balance making progress, knowing what a safe speed is for the road conditions, weather, traffic and other road users, passenger comfort, not hesitating etc.

Ive seen the one where you shouldnt drive faster than the distance you can see ahead to be able to stop.

Someone told me to deduct 2-3mph for each hazard I see but im not sure that i want to be doing maths when i should be concentrating on the road.

[Custom24]

Ive seen the one where you shouldnt drive faster than the distance you can see ahead to be able to stop.

Someone told me to deduct 2-3mph for each hazard I see but im not sure that i want to be doing maths when i should be concentrating on the road.

The first is the right way to think about it, the second I've never heard before but doesn't make a lot of sense to me. 2-3mph deducted from what? Some hazards are more important (and might require you to go slower) than others.

So, let's go back to the first one. A more expanded version is that you should always be able to stop, on your own side of the road, in the distance you can see to be clear, and which can be expected to remain so, given what can be reasonably expected to happen, allowing margin for safety and error. Sounds like a mouthful but much of advanced driving is right there.

Firstly, do you know how long it takes to stop? Theoretical distances as well as practical experience? Including reaction time. In the dry, in the wet.

Secondly, what things can you do to increase the distance you can see to be clear?

What things might be expected to change how far ahead will remain clear?

It's all about developing a feel for these things, and being honest with yourself. Someone told me they drive along, and in the back of their mind they are thinking "Can I stop, can I stop, what if he pulls out, can I stop, can I stop, what's just around that bend, can I still stop" and as long as the answer is yes, he is happy.

Finally, "reasonably be expected to happen" is a good phrase. We can only reduce, but not eliminate the risk, when driving, so if something unreasonable happens, you can only do your best and try to learn from it.

Hope this ramble is of some use.

[GJD]

Ive seen the one where you shouldnt drive faster than the distance you can see ahead to be able to stop.

Secondly, what things can you do to increase the distance you can see to be clear?

One thing you might be able to do, foxtrot_mike, is simply look further ahead. Observation is key to advanced driving and I believe it's very common when people first get involved with AD for them to find that they aren't looking as far ahead as they could/should - which is basically as far ahead as it's possible to see. You need to scan far ahead and close and beside and behind (mirrors for the last two) to keep an all round picture of what's going on, but if you miss out far ahead, you get a lot of information later than you could have done.

If you look further ahead and see it's clear, you may be able to drive a little faster. Of course it might not be clear, but then the earlier you see a hazard ahead, the more time you have to plan what you're going to do about it. And the more time you have to plan, the less likely you are to be hesitant or uncertain.

Regardless of all this though, don't ever feel pressured to drive faster than you are comfortable with. If anyone makes you feel that, they aren't helping you.

Gavin

[Astraist]

You need to match speeds to your visual field as possible. This enables for a fast, however safe and smooth ride, with the ability to react to any situation down the road. As said, this relies on the fact that you are looking as far ahead as possible in the given conditions.

[foxtrot_mike]

Thanks for this advice, so on the point ov observation is looking as far ahead as possible the most important part of observation but coupled with mid ground and fore ground, mirror checks etc

[michael769]

Thanks for this advice, so on the point ov observation is looking as far ahead as possible the most important part of observation but coupled with mid ground and fore ground, mirror checks etc

It is important to look at all areas that are visible to the driver -including to the sides. In the absence of any immediate hazards I'd say that vision be spread out evenly not emphasizing any particular zone, the aim is to scan the visual field (far, middle, near, sides, rear). With practice than can be done quickly enough that you don't miss anything

There is a natural tendency to "snowplough" which means concentrating on the nearest hazard then once dealt with moving on to the next - the best way to try to avoid this trap is to start your scan in the far distance and bring it in towards you rather than the opposite.

If there is some immediate hazard (or hazards) in the vicinity, then vision should spend more time in those areas, but you still need continue to scan to be able to see new hazards. The extent to which you pay more attention to the hazards in a particular zone of vision will depend to their relative priority based on your perception of the potential risk that they present.

The reason that you will often hear an emphasis on the distance vision is because many drivers tend to concentrate on their "comfort zone" of vision that is immediately in front of them and need some encourage to lift their vision into the distance.

[Discodriver]

Think bubbles!

There is a bubble of safety around your vehicle, as you go faster this bubble will increase in size, to the front, the sides and the rear. By the way the bubble isn't round it's more lozenge shaped. You need to influence the size of the bubble using system (position speed).

If your bubble is forced smaller by a hazard say a parked car, you need to either adjust your position so the bubble can stay the same size or change speed to make your bubble smaller. If a following vehicle enters your bubble you will need to increase you distance from the vehicle in front to keep your bubble the same size. A pedestrian appears at the kerb, they've walked into your bubble!

The same applies to lack of vision, if your bubble extends beyond what you can see, you must reduce the size of your bubble ie slow down or change position. Bubbles don't bend round corners!

Only you can decide the size of your safety bubble.

Now where'd I put my mushroom tea

[mitchr]

Think bubbles!

Mark what a brilliant way of describing it

[jcochrane]

Think bubbles!

Mark what a brilliant way of describing it

Also used to be known as a cacoon of safety which I think sounds very protective:)

[jont]

Think bubbles!

Mark what a brilliant way of describing it

Also used to be known as a cacoon of safety which I think sounds very protective:)

Or even cocoon

[jcochrane]

Or even cocoon

Definitely better than an African bean.

[fungus]

Remember also, that when driving on a single track road, or one where there is insufficient room for two vehicles to pass comfortably, you need to be able to stop in half the distance you can see, or can reasonably expect to remain clear.

[7db]

It is important to look at all areas that are visible to the driver -including to the sides

Mike makes a good point. You're not using the limit point (furthest you can see) but the point where the nearest surprise might reasonably come from. In urban situations this is considerably closer than the limit point.

[foxtrot_mike]

But in terms of speed you cant be doing 5mph because there are people waiting on the kerb to cross so its more about forward observation.

But it does still leave the question what is a safe speed.

[ScoobyChris]

But in terms of speed you cant be doing 5mph because there are people waiting on the kerb to cross so its more about forward observation.

I think we have to credit people on the pavement with some intelligence so, for example, they're a lot less of a hazard than an unrestrained child or dog on the pavement who are less likely to be aware of the dangers of the road. So in your assessment of a safe speed you have to decide how much of a hazard something poses.

The other aspect is that you can may be able to further reduce risk by positioning away from them on the approach and/or drawing their attention to you.

Chris