A Crash Course in Cycling (or, why everyone should be a cyclist)

[Psychosplodge]

Rather her than me.

[Wolfshade]

Gustaf Håkansson – the 'steel grandpa'
(full story: [url]http://www.theguardian.com/environment/bike-blog/2013/dec/11/gustaf-hakansson-sweden-cycle-race[/url])


Short story: Gustaf won a 1,000 mile race after being told he was too old to take part.

Longer story: The year was 1951, Gustaf a spritely 66-year-old signs up to race in a 1,000 mile race traversing most of Sweden only to be told that he had neither the strength nor the stamina to compete with the other racers at half his age.

Unpreturbed, he cycles 600 miles to the starting line and on the race day turns up with a homemade bib with a number 0, his trusty roadster, panniers, mudguards and a lamp.

Five days, five hours and 1,000 miles later rather than seeing a slender 30-something cross the winning line, this wizened grandpa comes flying over the line with his beard blowing in the wind. The second place was over a day behind him.

Håkansson of course cheated, well as much as someone not allowed in a race can cheat. The other riders were forced to stop and meet at a check point at the end of the day. Gustaf had no such truck with ideas, instead he stopped for an hour for a quick nap then back on the road.

Media at the time was less interested in the race as when the steel grandpa would carp it, with police trying to stop him to have a medical, he laughed passed them. He did befall one problem, with 800yrds to go he gain his first puncture. Dismounted and pushed his bike then with a few yards to go remounted to cross the line.

[Wolfshade]

Wow:

[DarkLink]

[url]http://www.thetimes.co.uk/tto/public/cyclesafety/article3941085.ece[/url]

At the top of the video shows how priority lights for roundabouts work.

What it shows is that people fundamentally do not understand how people will use them. What would end up happening, unless the cycle lane was physically segregated, upon seeing the cycle light was red and the motorist light was green the cyclists would just merge and be on the roundabout anyway... I am also concerned what this additional delay in the timings would have on the through put of the roundabout and how it would interact with all the other traffic light controlled junctions in the area.

[Traffic light timings are a complicated business and how they interact with other nearby junctions is even more so, so to optimise them is a seriously non-trivial excercise]

Yeah, while roundabouts reduce fatal car accidents, they tend to increase minor collisions. Which isn't a big deal for cars, but minor collisions aren't so minor for cyclists.

[Wolfshade]

That is an interesting view point, over here a significant number of junctions are round-a-bouts so the consequence on collision rates is not investigated. Looking at the articles I wonder how much of that is because they are not common place, whereas over here they are. The preference for them is more to do with the increased flow rates through a junction, but then they mess about with them with traffic light controls and different lane controls, i.e. some have two or three concentric lanes, others have lanes that spiral out from the centre.

[DarkLink]

I don't know about the priority lights, but I'm just speaking as a civil engineer. Albeit transportation was not my main focus, but the rule of thumb for roundabouts is that you have more accidents of less severity. The reason is pretty simple. Roundabouts have a lot more moving parts, coming from awkward directions that makes it difficult to see if you're going to hit someone if you try and merge over or something, whereas a traditional intersection you just stop at red, go at green, and you don't have to worry about getting clipped from behind. However, since all the traffic in a roundabout is going the same direction at low speeds, cars just kind of bump into each other and leave a fairly minor dent. In a traditional intersection, if someone blows a red light and tbones someone, that's two totaled cars and probably a few hospital trips.

Now, I haven't really studied the priority light stuff, but it seems to me at a quick glance that it kind of defeats the purpose of the roundabout. Roundabouts keep traffic moving more smoothly than a traditional intersection, at the minor expensive of introducing more complexity that increases the minor accident rate. You get generally higher volume and lower major accidents. Adding lights back in removes the advantage of higher volume, and if people blow through red lights in normal intersections they'll blow through them in roundabouts as well, so I don't see there being an advantage in major accidents.

Just my initial thoughts after watching the video.

[Wolfshade]

No it is quite right, though sometimes if the different feeder streams are not sufficiently balanced then the roundabout will become in effect closed to certain directions which is then countered by using lights to balance, though this works best on roundabouts which are large enough to allow multiple green lights on different sections of the round about at the same time, though of course this isn't quite as good as when you have a nicely balanced exit/entry points.

I was just wondering if there were a cutural bias between areas that have roundabouts as part of the normal traffic infrastructure like in the UK, to them being a much rarer beast in the states.

Let us see what mythbusters say:


Of course also on the down side is that roundabouts take up much more room, but seem to deal with more than 4 directions easier, though with a grid layout system that is dominant in the states (and other cities) this is less of a problem.

I think in terms of cycle friendly, minimal impact the dutch solution is the nicer one, there is an "outter ring" that is bike only


Of course then there are some round abouts which are beyond help:

[DarkLink]

It's definitely true that you can't just freely swap out lights with roundabouts. Each has its advantages, and there are places where one is clearly better than the other. If you need to place five roundabouts concentrically about a central roundabout, you probably should have just stuck with traditional lights. But sometimes city planners are like "oooohhhh, pretty, can we have one", and engineers just hang their heads and sigh.

[Psychosplodge]

I'd imagine the magic roundabout probably flows better than lights would, especially at rush hour.

[Wolfshade]

The magic roundabout flows really quite well, the issue comes when it is used by non-locals.