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Are Roads Safer With No Central White Lines?
Press2ToContinue writes: White lines along the center of roads have been removed in parts of the UK, with some experts saying it encourages motorists to slow down. So is it the beginning of the end for the central road marking? You are driving along the road when the dotted white line that has been your companion — separating your car from oncoming traffic — suddenly disappears. One theory is that you will slow down, making the road safer. What could possibly go wrong?
Good points, fortunately in the UK we have very few multiple lane roads and the removals are generally done where accidents show that people tend to speed because they feel too safe and should be reminded of both their own and others' vulnerability. It's recently happened near where I live, on a long slow bend where people were speeding up just before the crest of a hill and hugging the centre due to not seeing over that crest. The results have been immediate, people now tend towards the sides of the road and drive at a speed appropriate to the dangers. The 'theorists' predicting the end-of-the-world still claim that the evidence is 'wrong' and probably always will. Mebbe we should reward the understanding of stats rather than maths?
...when they finally go big time, given that the white lines currently are used to guide them on multi lane roads.
No need to wait for autonomous vehicle.
Current safety devices use it already:
- Lane Departure Warning:
vehicle uses the contrast of white lines on dark asphalt to guess where the lane is, and can either alert the driver (e.g.: Volvo cars) or correct course (e.g.: BMW) to stay in the lane. The driver needs to explicitly switch on the turn signal to tell the car that he indeed intend to turn the car.
No lines, not easy for the car to tell what exactly the trajectory should be. Whereas humans can more or less guess based on the surrounding and know where the "virtual lane" should go (and TFA's idea is that this guess-work will force drivers to be more prudent and slow down. My own feeling is that the first 2 weeks, the drivers will be watchful, then they'll get used it, and then everything will be back to normal)
- Forward Collision Avoidance:
vehicle have a forward facing radar that can detect other vehicle in front. So the car can see if the other in front breaks (when they are both in the same lane, i.e.: a traffic jam) and automatically slow down the cruise control (and in some car, resume driving once the traffic jam clears and the car in front starts again).
Also, the cars can detect incoming vehicle or vehicle that are on a crash course and prevent by applying breaks.
For that to work, again the car's computer need to have some basic idea of where lanes are. Other wise, there's a risk that the car will hit the break, even if the stoped/slower vehicle was in another lane, or the incoming car is in the other half of the road (like in TFA's case).
It seems similar to what i believe they did in the netherlands where they removed any distinction between the road and the pedestrian areas which apparently slowed down traffic.
...well at least, pedestrian and cyclist collision avoidance (more usually called "City Safety" by constructor, and currently slowly becoming a strandard option on most vehicle in europe), is entirely Lidar-based or shape-recognition based.
(i.e.: the car doesn't stop on its own because you're dangerously close to a pedestrian area or a bicycle lane, but because it recognised the object in front of you).
So at least *that* idea isn't disrupting existing safety device. But still...
I'm more proponent of some European city which have buried some of their highway network underground.
I don't think that forcing people to think about the security themselves by removing safety marking will actually work on the long term.
I strongly suspect that people will slowly adapt and get used to the missing markings, and start driving as carelessly as before.
If you think about it, large swaths of road miss markings, specially in developing countries. And those countries aren't exactly known for lower incident rates (though other reason, like vehicles to broken to be road-safe, missing driving education, etc. are other factors in play).
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Another favourite trick in the Netherlands (which is what I'm guessing you're posting about) is to have two bicycle lanes marked on both sides, leaving a normal road that would normally be too small for two cars to pass. This causes cars to drive in the center of the road, forcing them to drive more slowly:
http://www.brommerenscooterrij...
Another idea is that of a "shared space", having motorist mingle with pedestrians and bicyles, again forcing them to slow down:
https://www.allianz.com/v_1428...
What GP is ignoring is (1) that speed enforcement doesn't really work most of the time on smaller roads, as the proportion of cops to small roads will always be low, and (2) that speed enforcement itself causes people to drive in certain ways (braking when they see cop/radar,
None of these "environmental engineering" solutions will be a panacea: some will work in some conditions, but not in all. For example, the jury is still out on the new "shared space" between Amsterdam central railway station and ferry terminal. Ultimately, the question of what solution to use should not be political, but empirical: given a set of road conditions, what is the design that optimizes safety (or throughput, or speed, or whatever you want to optimize --- which is a political question).
What GP is ignoring is (1) that speed enforcement doesn't really work most of the time on smaller roads, as the proportion of cops to small roads will always be low,
But cops are not needed for speed enforcement. Automatic speed cameras mail you a fine - no cop involvement beyond filling the networked printer with paper & delivering the output to the post office.
My problem with shared space is when there is an accident, who is at fault?
Based on my neighborhood (no yellow lines), when there's an accident the police won't assign blame, the insurance companies will say its too hard to tell and split the cost 50/50, and then the other guy will claim he was injuried, so he has over 50% of the cost. It doesn't matter he was going 40+ on a 25, that he was on my side of the road (I'm inches from the curb on a raid that is more than four car widths wide). Since the roads are so wide, typically I can avoid the idiot drivers; with shared space, you are assuming the other people will slow down or get out of the way. That may be true in general, but what happens when they don't? If they brag about hitting 40 on a residential street that dead ends after 20 houses (10 each side), why would I expect them to slow down due to shared space?
Those 'otherwise clear stretches' that come with hidden intersections and entrances/driveways, you mean?
Actually the cycle is a bit more interesting than that.
You institute a charge.
People don't want to pay to sit in traffic so they don't.
Traffic gets cut down a lot.
Now people see a different sum altogether: for a nominal charge, I get to drive when the roads are mostly empty because nobody else wants to pay. Suddenly it's worth paying.
A lot of people do the same math.
Soon the road is congested again, but now everybody is paying and because they are already doing so - they now rationalize the cost away.
So the authorities raise the charge yet again...
Traffic jams are a prime example of market failure, in this case due to externalities, the vast bulk of the cost of your choice to drive (as opposed to say - taking the train) is not paid by you but by other people (and that's without considering climate change costs). A lot gets amortized over everybody else who drives (they all take longer to get there - time has value), some gets paid in medical bills from smoggier cities etc. etc. etc.
If you had to personally bare the full cost of driving, far fewer people would choose to drive and the market would function correctly. Traffic jams would be virtually non-existent and those who have to drive would be rewarded for their expense with very fast trips indeed.
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One would assume that after 10 years there would be some study on the effectiveness of the approach or other data available. A quick Google search turned up a government report done in London that measured speed differences both before and after. It doesn't report to the same level as a scientific study, but they did include a control for measurement, so presumably there is a more detailed version of the publication that details the methodology.
This particular study is limited in that it's concerned with roads where the speed limit is 30 mp/h (48 km/h) so it may not be reasonable to conclude it works on roads with higher speed limits, but for lower-speed city roads it does, in fact, appear to result in a natural reduction in traffic speed. They also point out it has the added benefit of reducing city work on roads (the roads don't need to be completely shut off for repainting) which I think some people would agree is worth it for that reason alone.
The report I linked above refers to a few other studies or reports, but does not provide a citation, so I can't look them up directly, but it would seem that there is a fair bit of support for removing the lines, at least in specific circumstances. Whether that holds true for other cases remains to be seen, but there is reasonable empirical support for doing it in urban areas and it would be something to study in more remote roads with higher speed limits.
Taking away any objections to removing the lines... the idea that this would cause people to slow down any longer than it would take them to get used to no lines is silly. There are plenty of large stretches of minor highway through out the midwest that do not have lines and there are still people still doing 90 - 100 mph on them when the speed limit is 60 - 65 mph.
Here's a well-traveled street straddling Beverly Hills and Los Angeles. It has no longitudinal traffic markings, and particularly from 3:00PM to 7:00PM has heavy traffic. The accident rate is modest, particularly given its narrow width and placement parallel to and between two major arterials.
Here's a well-traveled street in Fairbanks, AK. From October until April there is regularly snow that can quite effectively cover lane markings for days or months at a time. For example: I noticed this morning, only because the packed snow and ice had finally worn away enough to make the markings faintly visible, that I was driving through a painted median. A week ago I noticed three cars side-by-side to make left turns into two receiving lanes because snow had obscured the lane markings; they worked it out when the light changed and nobody died.
Three years ago, as the traffic & safety engineer, I was designing the signs and markings for a rural two-lane road that hadn't been previously paved. One discussion was the necessity of the inclusion of longitudinal markings. In the end, we painted the center lines and excluded the edge lines.
In the US, the MUTCD establishes a base requirement for center line markings on roads "that have a traveled way of 20 feet or more in width and an ADT of 6,000 vehicles per day or greater" or on two-way roads "that have three or more lanes for moving motor vehicle traffic." On many roads, center lane lines are already optional and their exclusion isn't an inherent problem. I might argue differently about reactionary idiots, however.
Presumably if the same number of people are trying to make the commute but at half the speed, then there are likely to be more cars on the road at the same time, that can't be good for accident rates, not to mention road rage incidents.
Nullius in verba