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Comment by apparent | Hacker News Reader

It is more dangerous to be slow and have people constantly merging in front of you, rather than be slightly faster and not have all the merging. Accidents happen when vehicles are going different speeds, all things equal.

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That seems like a surprising enough statement to be backed up by data. What is your source?

Everything I've read points toward larger margins of safety (longer distances, slower speeds) being safer.

See e.g. https://publications.lib.chalmers.se/records/fulltext/252480...

Obviously it is safer to have longer follow distances, all things equal. But you don't accomplish that if you leave a long follow distance that is cut off a few seconds later by another car trying to get ahead. You end up with a constant stream of cars cutting your follow distance to less than what it would have been if you had just stayed slightly closer to the car in front of you.

We don't live in an ideal world, and having a bunch of cars merging in front of you definitely makes you less safe than having a static situation. I try to make sure I can see through/around the car in front of me, so that I have advance notice of what's happening down the road.

American road laws are insane here. The law should be simple; you must be in the outside lane at all times unless you are overtaking, and once you're done overtaking, you should merge back into the outside lane.

https://www.highwaycodeuk.co.uk/overtaking.html

As far as I know that’s the law in every state I’ve driven in, but enforcement is pretty much nonexistent. Some states like Texas or Louisiana might have signs reminding people to stay out of the inner lanes except for passing but I’ve never heard of anyone getting a ticket over it. What’s enforcement like in the UK?

For example, the specific law in California: https://leginfo.legislature.ca.gov/faces/codes_displaySectio...

Vigorous.

Confusingly, the slow lane is called the "inside lane" in the UK, even though it's on the edge of the road and the fast lanes are in the middle.

That used to be the case in Ireland too, but confusion due to cultural contamination means pretty much everyone moved to numbering lanes (from the "outside"/"slow"/leftmost lane).

I wish.

Seems like this is the only place where the verge is in the inside.

I've been driving in Ireland for 30 years and I've never heard anyone number lanes. For me it's left/slow; middle; or right/fast lane.

When I did my B license test probably about 30 years ago, the Rules of the Road all referenced inside/outside lanes. When I did my CE license last year, it had been updated to only use lanes 1, 2, 3 etc.

Obviously fast and slow are just colloquial terms.

That seems rather inefficient on an 8– or 16–lane road.

Why? If everyone followed the rules the lanes would segment into slowest on the right, with gradually increasing speed to the left and people moving between the lanes as needed to overtake. It would be far far far better than the chaos of having to move across all the lanes of traffic all the time because there are random campers driving below the speed limit in every single lane.

First, everyone switches right as soon as there's a gap in a righter lane, so lots of unnecessary switching. Second, the right lane is always full making it hard to merge on or off the highway. Third, the leftmost lanes are underutilized when they could be filled with people who have a long way to go until their offramp.

That's fine when traffic is light. At rush hour, all lanes are full and nobody is overtaking.

You might be a bad driver and not even know it.

My decades-long impeccable driving record tends to indicate otherwise. I just don't drive as if I lived in the fantasy land where leaving a long follow distance means I have a lot of room in front of me. It doesn't. It means I get cut off, and the follow distance ends up being shorter than it would have been had I just been following at the same distance as all the other cars on the road.

It is possible of course that the highways you drive are just too busy and the max speed is actually set too high for how busy the road is. That happens more than you'd want because lowering the max of a highway is always an unpopular thing to, even if it's needed.

Still, I tend to find that people underestimate the danger of short distances. Often it's just better to accept a 100 cars going in front of you than to shrug off following someone at 1.5 seconds. It can go well for years because crashes are rare, but when you are in a crash you will be royally screwed when you don't have the reaction distance needed.

This assumes that you can actually maintain a 3 second follow distance. On some roads, you simply cannot, and an attempt to maintain such a distance leads to increased danger from all the cars that cut in.

Simply put: follow distance is not a unilateral decision.

That's what I mean with 'the road is too busy'. If you can't maintain a 3 second distance the speed needs to go down until you can. But you are right that this is sadly not something you can always do on your own.

I'm still convinced people decide way too soon that the 3 second distance is more dangerous. You might be right if people are constantly cutting in the moment you leave a gap, but if someone cuts in every 5 minutes you're still safer off with the gap.

This is dangerous nonsense. It's basically just a justification people find in order to feel good about their unsafe driving.

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