Mark, that is very important topic. Road diet is similar to healthy food. It has so many benefits for cities. But eventually, pioneers of the medical profession will accept only chemical drugs and surgical operations. No one will talk about the benefits of diet. Also, radical road designers everywhere will ignore such theory and will always talk about Road Standards and specefications.
Hey Mark, great article! I see you attracted the usual comments.
One piece of food for thought:
I’ve decided I don’t like “road diet” as an expression. While it makes sense from a certain point of view, I also think it provokes a defensive reaction, because it strongly implies that roads are “bad” in the same way that overeating is bad. And perhaps you or I feel that way, but, a lot of people knee-jerk and stop listening.
So, other things I’ve thought about are “safety improvements” or “right sizing” or “tailoring,” phrases like that. There probably isn’t a one-size fits all catch phrase that will work, because as soon as it catches on with urbanists it’ll polarize and about half the country will learn to dismiss it as culture war bait.
But you yourself pointed out the nuance, which is so important. We don’t need to be anti-car or opposed to driving to want safety and cost effectiveness. Those are universal priorities. And when I focus on those aspects I find its more persuasive to more people.
Oh yeah, that’s good! I think the photos of giant empty roads are compelling. Then saying “what could we use this space for instead?”
One exercise I recently saw in Denver, where they’re shrinking some of the major arterials, was to flip the narrative about traffic. Instead of saying “this road has heavy traffic at rush hour” they said “this road is significantly underutilized for 23.5 hours each day, creating safety hazards and wasting a lot of money maintaining excess capacity.” 👏
No biggy to shrink Nebraska Ave in Tampa as it runs a few blocks east of I275. But it's achieved none of the things y'll are talking about with cyclists and buses.
>Anthony Downs’ Triple Convergence theory, which says that expanding roadway capacity will eventually lead to more drivers using the improved roads, negating whatever capacity improvements have been built.
Negating because the proposed benefit is that travel times will go down. When they don't go down, or instead actually get worse, "negating... improvements" is the right description of what happened.
There's a slim-to-none chance that the cost/benefit is a positive ratio for drivers since I don't think that travel times will even stay the same. I think they'll increase, because that is the observed pattern when this happens. So, public funds get spent on a solution that makes everyone use more fuel and spend more time in a car. The benefits are limited to people who can buy cheaper property, further away from urban centers, and for people who sell petroleum products and cars. The costs are bore by taxpayers, existing route drivers, and anyone who lives near the expansion.
There are ways to handle growth of population that don't add lanes.
Of course, Houston's population has grown by at least 25% in the last 25 years, depending on how far out you go. These anti-car theories usually ignore the fact that population growth exists, and not building roads would make things worse off.
Plus, cars may shift from local roads to the expressways. Even with traffic, the expressway may still be faster than local roads with stop lights, crosswalks, waiting behind cars making turns.
And yes, make it harder to drive, and people will drive less... they will tend to stay close to home. I go downtown less than I used to because of congestion, and it means that even if there are more pedestrians hanging out, many businesses that serve the region lose out.
Trucks are the lifeblood of modern economies. If congestion gets bad enough, people will leave. It may also drive up housing prices so there is less diversity - the basis Von Thunen model of cities has a slope based on transportation cost increase the slope and the core might end up being only for the rich, though if the cost of land is high, people may also move farther out.
The article isn't anti-car. And nobody is advocating to stop building roads. My argument is more nuanced. The point is that many cities have so much excess road capacity that using a single lane of a 6 lane street to build a shared use path or protected bike lane would barely impact traffic. At the same time, the lane conversion would provide safe mobility options for people who chose to walk or bike. Options mean freedom.
If you go downtown less because of congestion, that's a transit policy failure, not a traffic engineering failure. Automobile traffic is a sign of economic health, and no amount of road building/widening will alleviate it (as per my article). We need more transportation options, not wider roads.
The standard "induced demand" example assumes no change in population and that people drive more until congestion reaches the same level - obviously we cannot run an experiment of 2 identitical cities and widen highways in one and not the other.
Let's talk about 3-4 types of roads. The example is usually adding lanes to a 4 lane plus limited access highway, like the Interstates. Then there are "Arterial roads" mostly in the suburbs, and either adding lanes, or maybe taking away a lane for bike lanes. Then there are inner city arterial roads, sometimes with parking outside of rush hour - which cannot be widened, but parking/lanes can be removed for bike lanes.
I live in Toronto and have seen massive changes since the 1960s - I started driving in the mid-70s. Toronto avoided the Detroit-level extreme of being criss crossed by expressways, but Toronto has had massive growth AND densification, and the provincial government is proposing new "400 series" (interstate type) roads on the fringes. Toronto council is left-ish and has been building bike lanes and limiting road capacity in other ways.
Toronto now also has the worst congestion in the North America. The provincial government is proposing a 30 mile long tunnel under the 401 - the busiest higheasy in Canada, and this is truly nuts. But there was also a debate a few years ago about removing a section of elevated highway on the waterfront - but the replacement for a 4-6 lane elevated highway would have been 8 lanes plus at grade, with signals... they went with moving the highway but keeping it elevated.
I drove Downtown on a Saturday night a few weeks ago. In the Financial Core, a 4 lane one way street had a bike lane added - with signals, then left turn only lanes added, with signals. Toronto also banned all cars from a long section of one main street, to speed up streetcars. Toronto has generally been waging a "War on the Car" - but Toronto also has probably the 2nd ot 3rd most extensive transit system - after NYC and Chicago.
I actually owned a row-house about as close to the Financial District as possible - beside Chinatown and the Art Gallery - from 2000 until last year. Getting there if the tenants had a problem became impossible, particularly with construction and road closures.
Toronto has been on the vanguard of densification and infill since the 1970s, then ani-sprawl laws and provincial densification policies since 2005, but also high population growth since 1990, cranked up even more since 2015. Housing prices skyrocketed. Now the federal government is micromanaging local governments to do "Abundance" style zoning changes.
The idea is something like trying to turn Chicago or Seattle into Manhattan. Toronto is still a great place to live, in large part because it is in Canada and Canada ranke almost up there with Scandinavia in many measures, but Toronto is getting harder to actually live in because of the congestion... and I live by the Lake in one of the areas made much harder to get too with elimination of expressway ramps and other changes.
In Toronto, we are doing a 3 stop subway extension - the price is no increaed to $10 billion CDN, about $7 billion USD.
Population growth and building transit is expensive, and the ridership volumes on this extension will be low and someone will have to pick up the operating losses.
Mark, that is very important topic. Road diet is similar to healthy food. It has so many benefits for cities. But eventually, pioneers of the medical profession will accept only chemical drugs and surgical operations. No one will talk about the benefits of diet. Also, radical road designers everywhere will ignore such theory and will always talk about Road Standards and specefications.
Hey Mark, great article! I see you attracted the usual comments.
One piece of food for thought:
I’ve decided I don’t like “road diet” as an expression. While it makes sense from a certain point of view, I also think it provokes a defensive reaction, because it strongly implies that roads are “bad” in the same way that overeating is bad. And perhaps you or I feel that way, but, a lot of people knee-jerk and stop listening.
So, other things I’ve thought about are “safety improvements” or “right sizing” or “tailoring,” phrases like that. There probably isn’t a one-size fits all catch phrase that will work, because as soon as it catches on with urbanists it’ll polarize and about half the country will learn to dismiss it as culture war bait.
But you yourself pointed out the nuance, which is so important. We don’t need to be anti-car or opposed to driving to want safety and cost effectiveness. Those are universal priorities. And when I focus on those aspects I find its more persuasive to more people.
Thanks for writing!
You make great points. I actually like the term "lane repurposing" better than "road diet".
Oh yeah, that’s good! I think the photos of giant empty roads are compelling. Then saying “what could we use this space for instead?”
One exercise I recently saw in Denver, where they’re shrinking some of the major arterials, was to flip the narrative about traffic. Instead of saying “this road has heavy traffic at rush hour” they said “this road is significantly underutilized for 23.5 hours each day, creating safety hazards and wasting a lot of money maintaining excess capacity.” 👏
How much of the reluctance to increase transit options is due to opposition from the industries that benefit from car centric design ?
No biggy to shrink Nebraska Ave in Tampa as it runs a few blocks east of I275. But it's achieved none of the things y'll are talking about with cyclists and buses.
>Closing or narrowing roads reduces traffic, and widening roads increases traffic.
Define 'traffic'. Is the claim that fewer lanes means higher vehicles/hour?
>Anthony Downs’ Triple Convergence theory, which says that expanding roadway capacity will eventually lead to more drivers using the improved roads, negating whatever capacity improvements have been built.
Why 'negating' instead of 'making use of'?
Negating because the proposed benefit is that travel times will go down. When they don't go down, or instead actually get worse, "negating... improvements" is the right description of what happened.
Seems like a win if more people get to make trips at the same travel time. The real question is whether this benefit outweighs the costs.
There's a slim-to-none chance that the cost/benefit is a positive ratio for drivers since I don't think that travel times will even stay the same. I think they'll increase, because that is the observed pattern when this happens. So, public funds get spent on a solution that makes everyone use more fuel and spend more time in a car. The benefits are limited to people who can buy cheaper property, further away from urban centers, and for people who sell petroleum products and cars. The costs are bore by taxpayers, existing route drivers, and anyone who lives near the expansion.
There are ways to handle growth of population that don't add lanes.
Of course, Houston's population has grown by at least 25% in the last 25 years, depending on how far out you go. These anti-car theories usually ignore the fact that population growth exists, and not building roads would make things worse off.
Plus, cars may shift from local roads to the expressways. Even with traffic, the expressway may still be faster than local roads with stop lights, crosswalks, waiting behind cars making turns.
And yes, make it harder to drive, and people will drive less... they will tend to stay close to home. I go downtown less than I used to because of congestion, and it means that even if there are more pedestrians hanging out, many businesses that serve the region lose out.
Trucks are the lifeblood of modern economies. If congestion gets bad enough, people will leave. It may also drive up housing prices so there is less diversity - the basis Von Thunen model of cities has a slope based on transportation cost increase the slope and the core might end up being only for the rich, though if the cost of land is high, people may also move farther out.
The article isn't anti-car. And nobody is advocating to stop building roads. My argument is more nuanced. The point is that many cities have so much excess road capacity that using a single lane of a 6 lane street to build a shared use path or protected bike lane would barely impact traffic. At the same time, the lane conversion would provide safe mobility options for people who chose to walk or bike. Options mean freedom.
If you go downtown less because of congestion, that's a transit policy failure, not a traffic engineering failure. Automobile traffic is a sign of economic health, and no amount of road building/widening will alleviate it (as per my article). We need more transportation options, not wider roads.
The standard "induced demand" example assumes no change in population and that people drive more until congestion reaches the same level - obviously we cannot run an experiment of 2 identitical cities and widen highways in one and not the other.
Let's talk about 3-4 types of roads. The example is usually adding lanes to a 4 lane plus limited access highway, like the Interstates. Then there are "Arterial roads" mostly in the suburbs, and either adding lanes, or maybe taking away a lane for bike lanes. Then there are inner city arterial roads, sometimes with parking outside of rush hour - which cannot be widened, but parking/lanes can be removed for bike lanes.
I live in Toronto and have seen massive changes since the 1960s - I started driving in the mid-70s. Toronto avoided the Detroit-level extreme of being criss crossed by expressways, but Toronto has had massive growth AND densification, and the provincial government is proposing new "400 series" (interstate type) roads on the fringes. Toronto council is left-ish and has been building bike lanes and limiting road capacity in other ways.
Toronto now also has the worst congestion in the North America. The provincial government is proposing a 30 mile long tunnel under the 401 - the busiest higheasy in Canada, and this is truly nuts. But there was also a debate a few years ago about removing a section of elevated highway on the waterfront - but the replacement for a 4-6 lane elevated highway would have been 8 lanes plus at grade, with signals... they went with moving the highway but keeping it elevated.
I drove Downtown on a Saturday night a few weeks ago. In the Financial Core, a 4 lane one way street had a bike lane added - with signals, then left turn only lanes added, with signals. Toronto also banned all cars from a long section of one main street, to speed up streetcars. Toronto has generally been waging a "War on the Car" - but Toronto also has probably the 2nd ot 3rd most extensive transit system - after NYC and Chicago.
I actually owned a row-house about as close to the Financial District as possible - beside Chinatown and the Art Gallery - from 2000 until last year. Getting there if the tenants had a problem became impossible, particularly with construction and road closures.
Toronto has been on the vanguard of densification and infill since the 1970s, then ani-sprawl laws and provincial densification policies since 2005, but also high population growth since 1990, cranked up even more since 2015. Housing prices skyrocketed. Now the federal government is micromanaging local governments to do "Abundance" style zoning changes.
The idea is something like trying to turn Chicago or Seattle into Manhattan. Toronto is still a great place to live, in large part because it is in Canada and Canada ranke almost up there with Scandinavia in many measures, but Toronto is getting harder to actually live in because of the congestion... and I live by the Lake in one of the areas made much harder to get too with elimination of expressway ramps and other changes.
Expansive public transit is needed - no more roads. I worked for 1 year in Houston.
In Toronto, we are doing a 3 stop subway extension - the price is no increaed to $10 billion CDN, about $7 billion USD.
Population growth and building transit is expensive, and the ridership volumes on this extension will be low and someone will have to pick up the operating losses.