We use streets every day and yet we rarely think about them unless they remain unplowed, potholed or closed — which happens all too often in the Twin Cities. Weather has a lot to do with why our streets take such a beating, but our development patterns since World War II also have a lot to do with why we have such a hard time maintaining them.

That point became clear when Joe Minicozzi came to town a couple of weeks ago. The principal of Urban3, an urban planning consulting firm in Asheville, N.C., Minicozzi has shown communities around the country why they have fallen so far behind in fixing their streets, and his answer differs markedly from much of the rest of the civil engineering community.

The American Society of Civil Engineers (ASCE) gives the nation a "D+" in its annual infrastructure report card, arguing that we spend about half of what we should annually on maintaining roads. The ASCE says government needs to spend more money on infrastructure, a lot more: $3.6 trillion by 2020.

Minicozzi sees the situation differently. He shows how our poorly maintained streets stem largely from the low-density developments that arose in this country over the past 70 years, resulting in an enormous mismatch between the cost of fixing our extensive infrastructure and the taxes generated by sprawl. He makes his case with compelling three-dimensional maps of the data, showing the extent and depth of the problem in all but the most built-up parts of our cities.

How did we get in such a fix? Before World War II, communities remained relatively compact and built streets in an incremental fashion, as development occurred, with enough density and mix of uses to generate the tax revenue needed to fix the roads in the future.

After the war, large-scale suburban development led to a vast increase in the amount of infrastructure needed to serve these low-density communities. Developers buried the initial cost of infrastructure in the sale of buildings and properties and then handed the roads and sewers over to the municipalities to own and maintain.

That worked well as long as the new infrastructure needed little repair. Also, as Minicozzi observes, many communities saw this infrastructure not as a liability, but as an asset because developers gave it to them, even though a community cannot sell its roads. Such thinking led cities "to focus on the taxes that might flow from a development without adequately considering the land base they will use up or the costs they will incur," says Minicozzi.

He calls a community's land base its "raw material" and the tax base its "product." Cities have struggled financially by wasting their land base on low-density development and lowering their tax base with too many low-quality buildings. The fiscal health of a city, says Minicozzi, depends on the revenue per acre it receives, and simply put, "dense development produces a greater return to a community than putting tax dollars toward sprawl."

In a recent analysis of Lafayette, La., Minicozzi's firm discovered that taxes on the average house in that low-density city generated $150 annually for infrastructure repair, while the actual yearly cost of maintaining the city's roads and sewers came to $7,150 per household.

In Minnesota, residents often fight rezoning efforts that would increase density. But unless we want dramatically increased taxation or dangerously unrepaired roads and bridges, we have no choice but to increase the revenue per acre that density brings and to use the infrastructure that we have more efficiently.

Suburban communities like Edina, Golden Valley and St. Louis Park have looked to land along commercial and transportation corridors as places to increase density without disturbing existing residential areas. Mixed-used development has sprung up near light-rail stations in Minneapolis and St. Paul. And housing has started to replace surface parking lots — one of the most inefficient uses of our land base — across the Twin Cities.

But we have a long way to go. Overextended infrastructure and the low-density development that it serves puts us at a competitive disadvantage to other cities. The same day that Minicozzi presented to the Urban Land Institute's Regional Council of Mayors, Peter Frosch, vice president for strategic partnerships at Greater MSP, presented research showing that our region ranked fourth among 12 metropolitan areas in attracting and retaining talented people to help fuel the economy.

While that seemed like a classic case of Minnesota being above average, the three cities ahead of us — San Francisco, Seattle and Boston — all have equal or higher densities, more mixed-use neighborhoods, and more compact footprints than we do. As a result, they have a higher tax base and fewer miles of pavement to maintain, something that we should strive to achieve over time. And we will have one very good measure of our success: the state of repair of our streets.

Thomas Fisher is director of the Metropolitan Design Center at the University of Minnesota.