A blog for better streets and public spaces in Portland, Maine.

Thursday, November 19, 2009

The Difference Four Feet Makes

Over the long summer construction season, 3/4 of a mile of Read Street in Portland's Back Cove neighborhood was torn up and rebuilt as part of the city's sewer upgrades program. The project is nearly finished, and here's a photo of the new Read Street:



It may not look like much, but believe it or not, this represents one of the more significant livable streets victories for Portland this year. That's because the new Read Street is 4 feet narrower than the old Read Street - and while that in itself is a relatively minor change, it could be the start of a big trend across the city and even the entire state.

Obviously, narrowing the street - from 36 feet to 32 feet wide - is going to slow down traffic through the neighborhood. Especially when people start parking their cars on the street, and narrow the effective width of the street to 24' or 16'. That's going to make people safer, and it's why Read Street's neighbors fought hard for the change.

But for City Hall, there was a much more powerful argument for a narrower Read Street: it costs much less to build and maintain. Light duty pavement is about $3 a square foot, so saving 4 feet of width, over the .75 mile length of Read St., would save the city $3*4*.75*5280 [the number of feet in a mile]=$47,520 in construction costs - enough to hire a new teacher for the schools.

And that's just for the short term - the long-term maintenance savings will be even greater, since there will be less roadway to plow, salt, and sand, fewer potholes to fill, etc.

Then there's the fact that this whole project is designed to separate the storm sewers, which carry street runoff, from the sanitary sewers: the combined sewers that are being replaced had a nasty habit of overflowing into Back Cove during rainstorms. The new system will carry sewage from houses and businesses to the treatment plant, but most of the storm runoff from streets is going to be dumped into the Cove, along with whatever garbage might have been in the gutters. So the city is taking a general policy of reducing "impervious surfaces", in order to let as much rain as possible soak into the ground before it goes down storm drains.

Making the street 4 feet narrower gives falling rain less space to flood the street, and more space to soak into the ground. Along the 3/4 mile length of the project, there's going to be a total of 16,000 additional square feet of soil, grass, and tree roots instead of pavement. In a 2-inch rainstorm, that will prevent about 1700 gallons of runoff from polluting Back Cove.

So: the neighborhood gets a safer street. City Hall saves tens of thousands of dollars. Back Cove gets cleaner, and ratepayers pay less on sewer bills. Wins all around.

So how could this not catch on? The state DOT is projecting highway fund shortfalls of up to $380 million a year in the next decade. Spending money on unnecessary pavement ought to be something they'd want to avoid. But then again, the good old boys in Augusta just love pavement SO MUCH, it's hard for them to tear themselves away.

1 comment:

Turboglacier said...

If they decide to start narrowing the streets in the West End, they'll turn them from two-way-in-summer and one-way-in-winter into one-way-in-summer and no-way-in-winter! : )