Friday, 29 April 2016

Wide lanes

In much of North America and in some other countries, the goal on streets is often to have wide lanes for motor traffic. I believe this to be a mistake.

In the Netherlands, normally, access roads in the urban area is more or less 4.5 metres for a two way road. We aren't trying to have trucks overtaking each other. In fact, I'd suggest a law that prohibited vehicles over at least 7.5 tonnes, possibly down to 3.5 tonnes (1 tonne = 1000 kg) from entering an access road, but that's a different topic. On distributor roads, the lanes are typically 3.1 metres, although they can do down to 2.8 metres in some situations. And on the through roads ,the lanes are usually 3.25 for an autoweg, maximum speed of 100 km/h, and 3.5 metres for motorways, this also happens to be the standard for an E route as defined by the UN. Note that the width of the stripe itself isn't counted.

In North America, we generally see 12 foot lanes on many roads as advocated for by AASTHO. This is for the rest of the world who has joined the 21st century, 3.7 metres. Sometimes 11 foot lanes, or if you're like me, 3.3 metre wide lanes, are used in the urban area, and sometimes 10 foot lanes are used, or 3 metre wide lanes, although this is generally only used on downtown streets or in very limited situations. Sometimes 14 (4.2 m)-15 (4.5 m) foot lanes are used when a road manager decides to try using a "wide lane" as defined by vehicular cyclists, wanting the ability to have 4 (1.2 m)or 5 feet (1.5 m) for cyclists allowing a car 10 feet to overtake.

I believe the North American practice to be a mistake. It encourages speeding. I myself find it very hard to stay at 60 km/h if the lane is 3.7, or worse, 4.2-4.5 metres as is often done in the curbside lane, wide. I also find it to make it harder to predict the function of a road. 3.7 metre wide lanes officially limited to 50 km/h are wider than Dutch motorway lanes with a speed limit of 130 km/h. Obviously there is a problem with consistency. Another problem is that it takes away space we could use to make a road more useful. Let's use the city's plan for 107 Ave over Groat Rd as an example. The widths of the lanes is very wide. I added up all of the lane widths, then took the number of lanes, multiplied it by 3.1, or the standard width for a Dutch urban distributor road, subtracted this from the lane widths, and got a remainder of 4.3 metres. We have an extra 4.3 metres to use if we narrow the lanes down to the Dutch normal lane widths. We can add an extra 2 metres to the 2 metre wide shared use path, we can add a separate sidewalk for pedestrians alone, widen the opposite side sidewalk by .3 metres to bring it up to 1.8, the Dutch minimum. We can add more protection for the new cycle path by reorganizing the median layouts, but you can see that we just created a a cycle path and a sufficiently wide sidewalks, though a bit narrow by Dutch standards, just by making the widths better suited for the road.

Note that I eliminated the wide curbside lane. This will not harm cyclists who in the past may have vehicularly cycled here. This is because I allocated room for a completely separate path that is wide, and assuming you build the intersections correctly, IE to Dutch standards and best practices, absolutely nobody suffers by having the vehicular cyclists on a separate pathway. Not even you John Forester.

I imagine you wanting to ask me how a bus or truck will fit through. Put down your pitchforks and torches, and listen. Maybe even put up your hand as you were taught in school. The European, and by extension, Dutch, regulations surrounding trucks and buses also includes width. They have a legal maximum of 2.6 metres. What is our legal maximum? Also 2.6 metres. This goes for buses and trucks. There isn't a reason for oversize vehicles to come here, nor do we have any expectation of a tractor, so we can make a reasonable assumption that vehicles will not exceed 2.6 metres in width. And anyone with a basic understanding of math knows that 3.1 metres is much wider than 2.6 metres, 50 cm to be exact, or 25 cm on both sides of the vehicle. Still enough.

Our lanes really are too wide, and in some cases can restrict our ability to have quality cycling and walking space, sometimes even make it impossible to provide otherwise. By using our valuable lane space wisely, we can reduce speeding, make the speeds more in line with that should be expected of the road users and make space for cycling, walking and in some cases, even public transport.

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