Forget Driverless Cars, This Tiny Design Tweak Can Make Streets Safer

[jakeroot]

Pardon the ridiculous click-bait title, but that's Gizmodo for you.

Forget Driverless Cars, This Tiny Design Tweak Can Make Streets Safer

The article is basically about making the standard URBAN lane width 10 feet instead of 12, something I've always thought was a good idea. I know the idea of narrower lanes has been floating around for quite some time, but this article was on my FB news feed, and I just HAD to post it here.

Quick excerpt:

When designing our freeway lanes, engineers had to design them for much higher speeds than the speed limit that was posted–because they knew people would speed. Therefore, freeways were designed with much wider lanes than necessary. But that doesn't translate to city driving, says Speck:

Unfortunately, trained to expect this sort of behavior, highway engineers apply the same logic to the design of city streets, where people behave in an entirely different way. On city streets, most drivers ignore posted speed limits, and instead drive the speed at which they feel safe. That speed is set by the cues provided by the environment. Are there other cars near me? Is an intersection approaching? Can I see around that corner? Are there trees and buildings near the road? Are there people walking or biking nearby? And: How wide is my lane?

[roadfro]

Pardon the ridiculous click-bait title, but that's Gizmodo for you.

Forget Driverless Cars, This Tiny Design Tweak Can Make Streets Safer

The article is basically about making the standard lane width 10 feet instead of 12 feet, something I've always thought was a good idea. I know the idea of narrower lanes has been floating around for quite some time, but this article was on my FB news feed, and I just HAD to post it here.

Quick excerpt:

When designing our freeway lanes, engineers had to design them for much higher speeds than the speed limit that was posted–because they knew people would speed. Therefore, freeways were designed with much wider lanes than necessary. But that doesn't translate to city driving, says Speck:

Unfortunately, trained to expect this sort of behavior, highway engineers apply the same logic to the design of city streets, where people behave in an entirely different way. On city streets, most drivers ignore posted speed limits, and instead drive the speed at which they feel safe. That speed is set by the cues provided by the environment. Are there other cars near me? Is an intersection approaching? Can I see around that corner? Are there trees and buildings near the road? Are there people walking or biking nearby? And: How wide is my lane?

This concept is nothing new, although advocating a 10-foot lane width standard certainly is. I didn't read the study linked in the article, so some of my thoughts  may be conjecture.

Narrower lanes on a road does tend to have a psychological affect on drivers used to the standard 12-foot width. With narrower lanes, they may tend to think they are drifting more toward the line, so they generally slow down a bit in response. Thus, making lanes narrower is good for some areas where you would want to slow traffic down--downtown areas, central business district, heavy pedestrian areas, high bicycle lane use areas, etc. In essence, "complete street" or "road diet" situations.

With that said, if you have a major arterial roadway where the purpose is to move many vehicles, narrowing lanes may have a negative affect on the throughput, which affects capacity and delay.

[spooky]

This is true if you believe that vehicle speed is the only thing that affects a roadway's safety.

[Pete from Boston]

This is true if you believe that vehicle speed is the only thing that affects a roadway's safety.

That is a bit of a leap.  This is true if you believe that vehicle speed affects roadway safety.  It is a bit of a leap to say the implication is that it's the only thing.

[Pete from Boston]

With that said, if you have a major arterial roadway where the purpose is to move many vehicles, narrowing lanes may have a negative affect on the throughput, which affects capacity and delay.

There is quite a bit of momentum in some cities to put throughput second after multi-use accommodation.  This is actually fine  with me until it begins to shunt traffic into so few roads with so few alternatives that a lot of extra gridlock ensues.  It's rarely approached regionally. 

The idea is not that city streets are not the place for through traffic (though that's part of it) but that fewer people should be driving, period.

However, as someone who must drive regularly, I so far have not been offered good alternatives from the capacity-reduction community.

[spooky]

This is true if you believe that vehicle speed is the only thing that affects a roadway's safety.

That is a bit of a leap.  This is true if you believe that vehicle speed affects roadway safety.  It is a bit of a leap to say the implication is that it's the only thing.

I didn't see any mention of the other safety impacts of narrower lanes.

[Laura]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

[Brandon]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

That's because, and I've talked with urban planners on this, we've given into fire departments when they whine about the sizes of streets and their oversize trucks.  They really don't need huge articulated hook and ladder trucks everywhere.  They've conned us into thinking they do.  Most residential areas only need a smaller truck that can get up to 30 feet or so.

[PHLBOS]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

That's because, and I've talked with urban planners on this, we've given into fire departments when they whine about the sizes of streets and their oversize trucks.  They really don't need huge articulated hook and ladder trucks everywhere.  They've conned us into thinking they do.  Most residential areas only need a smaller truck that can get up to 30 feet or so.

And how many of those residential streets have on-street parking along both sides?

[jakeroot]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

That's because, and I've talked with urban planners on this, we've given into fire departments when they whine about the sizes of streets and their oversize trucks.  They really don't need huge articulated hook and ladder trucks everywhere.  They've conned us into thinking they do.  Most residential areas only need a smaller truck that can get up to 30 feet or so.

If they whine again, lets serve them a plate of Japanese food:

[jeffandnicole]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

That's because, and I've talked with urban planners on this, we've given into fire departments when they whine about the sizes of streets and their oversize trucks.  They really don't need huge articulated hook and ladder trucks everywhere.  They've conned us into thinking they do.  Most residential areas only need a smaller truck that can get up to 30 feet or so.

While that's true, a fire department sends what they have available.  If the nearby fire company has a smaller truck and a hook and ladder, are they going to say "Sorry, we can't fit both trucks.  We'll send one truck down, and you'll just have to wait 15 minutes for the next closest fire company to send their truck"?  Or, if the smaller truck is already out at a fire and another one occurs, will they say "sorry, you'll have to wait"...and leave residents wondering why they are paying for a hook and ladder that can't fight a simple fire?

Sure, these circumstances are few and far in between, but rarely are residents going to be calm and understanding when their house - or a neighbor's house - is in flames.

(I'm actually a bit fortunate in this regard - NJ has a lot of neighborhood fire houses.  my closest fire house isn't even my 'home' fire house...which is actually a few hundred feet further away.  But in the instance of a fire or incident in the neighborhood, I've always seen both companies respond anyway)

[Pete from Boston]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

That's because, and I've talked with urban planners on this, we've given into fire departments when they whine about the sizes of streets and their oversize trucks.  They really don't need huge articulated hook and ladder trucks everywhere.  They've conned us into thinking they do.  Most residential areas only need a smaller truck that can get up to 30 feet or so.

If they whine again, lets serve them a plate of Japanese food:

That fire truck looks like it is about to smile.

[cpzilliacus]

Anyone ever think about the impact on commercial vehicles?  Not just fire and rescue vehicles. 

Including delivery trucks,  refuse and recycle trucks (which can be very large)?  Even ambulances can be the size of medium-duty commercial trucks.

[jakeroot]

Anyone ever think about the impact on commercial vehicles?  Not just fire and rescue vehicles. 

Including delivery trucks,  refuse and recycle trucks (which can be very large)?  Even ambulances can be the size of medium-duty commercial trucks.

Plenty of countries have narrow lanes without any issue...the difference is, their drivers are properly trained. The size of vehicles should reflect the size of the road, not the other way around.

[Pete from Boston]

Just ask anyone on one of these streets that ever needed a dumpster delivered.

[andrewkbrown]

Yep. Andres Duany argues this same point in the book Suburban Nation. In particular, he mentions how residential streets have gotten wider to accommodate emergency vehicles. I find this amusing because there's no need to add extra width to a residential street for a fire truck - there isn't enough traffic, so an emergency vehicle could easily pass in the other lane.

That's because, and I've talked with urban planners on this, we've given into fire departments when they whine about the sizes of streets and their oversize trucks.  They really don't need huge articulated hook and ladder trucks everywhere.  They've conned us into thinking they do.  Most residential areas only need a smaller truck that can get up to 30 feet or so.

Actually, a 40-45 foot articulated ladder truck can navigate smaller streets and tighter turns than a 30 foot straight ladder truck, as both the front and rear wheels steer.

I never thought we'd make this turn, but the tractor-drawn aerial ladder I was riding in yesterday mangaged to easily make the right turn at this posted intersection, from the street where the gray SUV is, to the street seen with the white van going up the hill.
https://maps.google.com/?ll=38.929684,-77.043931&spn=0.000002,0.001184&t=h&z=20&layer=c&cbll=38.929757,-77.044202&panoid=VXYZFKc577Jkm8wngOJZ-g&cbp=12,159.2,,1,1

[formulanone]

This has nothing to do with driverless cars. I think it's okay for short stretches where irreplaceable nature can/should not be destroyed, or around historic areas.

It's a terrible idea for everywhere else. It would make it difficult to see around other vehicles and to dodge obstacles in the road. We already have Move Over laws nearly everywhere, more cyclists and pedestrians, and larger vehicles than before (over the past twenty years) due to increased federal standards. Not to mention less attentive drivers in all types of vehicles.

It's a dream for insurance companies and departments with tight budgets, but I see moving these ideas onto open roads or busy thoroughfares as pointless road-slowing tactics that I'd like no part of.

[Zeffy]

You could always make the streets like this and post it with a 25 MPH speed limit. You're not getting much higher than 30 on a road like this, trust me.

[Brandon]

You could always make the streets like this and post it with a 25 MPH speed limit. You're not getting much higher than 30 on a road like this, trust me.

Why not, it looks like a great place to hold a Grand Prix event.

[PHLBOS]

You could always make the streets like this and post it with a 25 MPH speed limit. You're not getting much higher than 30 on a road like this, trust me.

Such is definitely true here.