- 注册
- 2002-10-07
- 消息
- 402,141
- 荣誉分数
- 76
- 声望点数
- 0
We can save millions of dollars on new suburban roads by building bike tracks next to them instead of painting bike lanes on them, the city has realized.
It’s part of a big package of ideas for making Ottawa’s new subdivisions cheaper to construct that planners and developers have been working on for years, and probably the most obviously smart.
Roads for cars and trucks are paved atop layer after layer of stabilizing foundation; they have to withstand years of pressure from thousands of pounds of rubber and glass and metal. A cyclist weighs a couple of hundred pounds at most, and there’s no point, the city has realized, in building a road extra wide only to reserve a metre on either side of it for bikes. Cycle tracks next to sidewalks, on beds built to the lighter sidewalk standards, are good enough.
Better, in fact, because most cyclists prefer to be up and away from car traffic, protected from motor vehicles by more than a line of paint. So the city can save $41 for every metre of road we build by doing what cyclists want anyway.
It “simultaneously improves safety, reduces construction and lifecycle costs, and improves yield,” a progress report from the city’s Building Better and Smart Suburbs idea factory says. “Improves yield” means it takes up less space, leaving more room for houses. Getting higher yield from the same land means more people can share what does get built, spreading the costs out further.
An even bigger potential savings is no longer routinely building medians in the middles of low-speed roads. That’ll save $275 a metre, the city estimates, and make for smaller roads. The whole right-of way (the road and bike lanes and sidewalks and grassy strips in between) can be five metres narrower. Much nicer to cross or just be near.
The total savings from those two changes, for all the roads the city’s planning to build in the near future, is $12.1 million, or $87 a house.
City Hall has pushed really hard to get denser suburbs, realizing that sprawl is expensive and inefficient, and it’s succeeded impressively. The standard new subdivision is far fuller of rowhouses and townhouses than it would have been 20 years ago. We’ve still been using old low-density standards for the public things we build to make the suburbs work.
Not everything in the package of ideas will be as welcome as the bike tracks. The city figures it wastes a lot of space in new subdivisions with “dry ponds,” extra holding areas for rainwater when normal “wet ponds” that form part of a neighbourhood’s drainage system are full. Nearly all the time they’re just empty depressions in the ground and we can get away without them, the planners think — if we put up with more water pooling in the streets during heavy storms. This particular rainy weekend, that might not seem like as good an idea as it does when the dry ponds are really dry.
Letting builders use pumps to drain basements instead of burying pipes deeply enough to let gravity do it is another one, with the savings from that yet to be calculated. Sump pumps will save money in construction and save the city money when the shallower pipes eventually need to be replaced, but likely cost homeowners something more in maintenance.
Other ideas:
This is all still a work in progress, waiting for final reports and city council votes that won’t come for a while. It’s happening for a reason that might surprise you: Light rail.
To pay for the multibillion-dollar, decade-long construction effort, the city’s hiked the fees it charges developers — and, through them, eventually buyers — of new houses and condos for the city infrastructure the new residents will use.
We’re talking about a lot of money: more than $31,000 for every new single or semi-detached house outside the Greenbelt (townhouses and apartments are cheaper, and so is anything built inside the Greenbelt, but we’re still talking $10,000-plus). That’s up more than $1,000 from just a couple of years ago, and up $10,000 from 2009.
Why? Well, we’ve had a bus-based transit system, and the cheapness of busways was a key factor in setting Ottawa’s development charges; now that we’re upgrading to rail, the city’s charging more. Sanding down the charges for water pipes and roadways is a way of mitigating the spike. So far, the city and the building industry think they can save an average of $1,800 a house in upfront costs and long-term maintenance, but they’re still counting.
dreevely@postmedia.com
twitter.com/davidreevely
查看原文...
It’s part of a big package of ideas for making Ottawa’s new subdivisions cheaper to construct that planners and developers have been working on for years, and probably the most obviously smart.
Roads for cars and trucks are paved atop layer after layer of stabilizing foundation; they have to withstand years of pressure from thousands of pounds of rubber and glass and metal. A cyclist weighs a couple of hundred pounds at most, and there’s no point, the city has realized, in building a road extra wide only to reserve a metre on either side of it for bikes. Cycle tracks next to sidewalks, on beds built to the lighter sidewalk standards, are good enough.
Better, in fact, because most cyclists prefer to be up and away from car traffic, protected from motor vehicles by more than a line of paint. So the city can save $41 for every metre of road we build by doing what cyclists want anyway.
It “simultaneously improves safety, reduces construction and lifecycle costs, and improves yield,” a progress report from the city’s Building Better and Smart Suburbs idea factory says. “Improves yield” means it takes up less space, leaving more room for houses. Getting higher yield from the same land means more people can share what does get built, spreading the costs out further.
An even bigger potential savings is no longer routinely building medians in the middles of low-speed roads. That’ll save $275 a metre, the city estimates, and make for smaller roads. The whole right-of way (the road and bike lanes and sidewalks and grassy strips in between) can be five metres narrower. Much nicer to cross or just be near.
The total savings from those two changes, for all the roads the city’s planning to build in the near future, is $12.1 million, or $87 a house.
City Hall has pushed really hard to get denser suburbs, realizing that sprawl is expensive and inefficient, and it’s succeeded impressively. The standard new subdivision is far fuller of rowhouses and townhouses than it would have been 20 years ago. We’ve still been using old low-density standards for the public things we build to make the suburbs work.
Not everything in the package of ideas will be as welcome as the bike tracks. The city figures it wastes a lot of space in new subdivisions with “dry ponds,” extra holding areas for rainwater when normal “wet ponds” that form part of a neighbourhood’s drainage system are full. Nearly all the time they’re just empty depressions in the ground and we can get away without them, the planners think — if we put up with more water pooling in the streets during heavy storms. This particular rainy weekend, that might not seem like as good an idea as it does when the dry ponds are really dry.
Letting builders use pumps to drain basements instead of burying pipes deeply enough to let gravity do it is another one, with the savings from that yet to be calculated. Sump pumps will save money in construction and save the city money when the shallower pipes eventually need to be replaced, but likely cost homeowners something more in maintenance.
Other ideas:
- putting manholes 150 metres apart instead of 120 metres
- allowing more parkland to be in the form of small parkettes dotting neighbourhoods, instead of one big central spot
- laying in smaller water mains
- letting school drop-off zones be built roadside on city property instead of requiring them to be on the school’s own land.
This is all still a work in progress, waiting for final reports and city council votes that won’t come for a while. It’s happening for a reason that might surprise you: Light rail.
To pay for the multibillion-dollar, decade-long construction effort, the city’s hiked the fees it charges developers — and, through them, eventually buyers — of new houses and condos for the city infrastructure the new residents will use.
We’re talking about a lot of money: more than $31,000 for every new single or semi-detached house outside the Greenbelt (townhouses and apartments are cheaper, and so is anything built inside the Greenbelt, but we’re still talking $10,000-plus). That’s up more than $1,000 from just a couple of years ago, and up $10,000 from 2009.
Why? Well, we’ve had a bus-based transit system, and the cheapness of busways was a key factor in setting Ottawa’s development charges; now that we’re upgrading to rail, the city’s charging more. Sanding down the charges for water pipes and roadways is a way of mitigating the spike. So far, the city and the building industry think they can save an average of $1,800 a house in upfront costs and long-term maintenance, but they’re still counting.
dreevely@postmedia.com
twitter.com/davidreevely
查看原文...
