It's controversial because it is often more dangerous to drive on a bicycle lane, at least outside the Netherlands with its well designed bicycle lanes. There is a higher risk that car drivers will not see you when turning right at a crossing etc. In addition, you are exposed to car drivers or passengers who open the door without looking. On the road, with a safe distance to the right, you are annoying to cars but far more visible. For this reason, many bicycle enthusiasts have recommended people to ride on the road if there is no mandatory and well maintained bicycle lane.

At least that was the situation a few years ago when bicycle lanes were just narrow lanes directly next to the road or the sidewalk. As I wrote, it can work if done correctly (see the Netherlands). Perhaps the road planners and drivers have learned "their" lesson in the meantime. I say that as a car driver.

Hans Monderman was the world's most famous traffic engineer! ;)

https://en.wikipedia.org/wiki/Hans_Monderman

>Hans Monderman (19 November 1945 – 7 January 2008) was a Dutch road traffic engineer and innovator. He was recognised for radically challenging the criteria used to evaluate engineering solutions for street design. His work compelled transportation planners and highway engineers to look afresh at the way people and technology relate to each other.

https://www.youtube.com/watch?v=3Wte5-_gCDQ

>de Kaden shared space.wmv: Shared space traffic intersection in Drachten, The Netherlands. Traffic signals removed in 2002. The junction handles around 17,000 vehicles per day. One of many projects led by the late Hans Monderman.

https://www.youtube.com/watch?v=zpHlj5j7nyY

>Shared space intersection, Drachten - The Netherlands 3,824 views Apr 29, 2009 Drachten, Drift/De Kaden, shared-space-intersection. From the centre of expertise on bicycle policy: http://www.bicyclecouncil.org. The intersection Drift and De Kaden is an example of shared space in the purest sense. Despite a quite high traffic volume hardly any measures have been taken to regulate traffic.

https://www.youtube.com/watch?v=pqQSwQLDIK8

>Unbelievably busy bicycle crossing in Amsterdam: The Netherlands, Amsterdam, May 8, 2018 Bicycle and car traffic at the crossing Korte Prinsengracht and Haarlemmerstraat.

https://www.youtube.com/watch?v=bjBGokenEhQ

>Hans Monderman: Rethinking the design of streets and public space.

>An Urban Design London and Urban Design Group Lecture Hans Monderman has been one of the most significant influences on the current debate about the design of streets and spaces in the UK. A traffic engineer and road safety specialist from Northern Holland, he is celebrated as the pioneer of shared space as a means to influence speed and driver behaviour. Monderman has been the inspiration behind scores of towns and villages which work without road markings, traffic signs, signals, kerbs, barriers and bollards. ‘Most engineers, when faced with a problem, try to add something,’ he says. ‘My instinct has always been to take something away.’ Following a short introduction by Rob Cowan, Hans explains his approach, work and experiences. Copyright: Esther Kurland. Director. Urban Design London

Have you ever tried riding a bicycle in the city?

Bicycle lanes in many cities are close to unusable.

For example:

- they are right next to parked cars and you can't ride on them without constant fear of getting doored

- they abruptly stop and there is no obvious place where to continue riding

- cars park on the bicycle lanes

- bicycle lanes go right next to crowded bus stops and there are so many people that it's impossible to ride

- crossings are designed in such a way that you need to wait for three (!) traffic lights to cross a single road, leading to a waiting time of at least 3 minutes

There are only a handful of roads with usable bicycle lanes in my city. And guess what: In places where bicycle lanes are usable, people use them. Nobody rides a bicycle on the road if there is a usable alternative.

some more reasons from a UK perspective:

- if you want to turn across the road, you have to merge onto the road which can be dangerous and awkward, so it's better to be on the road for longer before you want to turn than you might expect.

- cycle lanes are often too narrow (if just painted onto an existing road), so push you closer to the curb than is really safe. i often feel like the best position would be on the edge of the cycle lane, but then cars will not overtake properly

- ungraded cycle lanes tend to fill up with the dirt and detritus that's flung off the road by vehicles if they're not cleaned regularly enough (this is especially a problem if there are bollards or other street furniture that is supposed to separate the bike lane from the road, as it makes them harder to clean)

- cars are more likely to cut you off when turning across a cycle lane, than if they are forced to overtake properly

most cyclists I've talked to here think the kind of cycle lanes we have are worse than useless

Almost all cyclists would cycle in bicycle lanes if they existed.

I beg to pardon.

This video came out yesterday and talks about this subject: https://www.youtube.com/watch?v=9pcAfeGCrUc

The vast majority of roads do not have separate cycle lanes - this is obviously not a good-faith argument.

And if a pedestrian has no sidewalk?

Pedestrians use much less space than cyclists and move slower, they typically also move away when they hear a car and most of them on such roads go in direction opposite to traffic flow so they see when a car approaches. Bicycles go in the same direction as traffic, sometimes swerve and go in small zigzag pattern, they don't have mirrors, don't look back and bicyclists are many times already tired from bicycling, they are also in more hurry than pedestrians (hurrying pedestrians also more often have accidents). In places where there are no sidewalks typically there are almost no pedestrians.