Gravel or pavement? Running costs to ground in exurbia

Between 1998 and 2007, Baldwin Township's population grew quickly and with that growth came mile after mile of new paved road.

These young roads are relatively easy and inexpensive to maintain for now, but they are aging at the same pace. This means that when it's time to overlay more bituminous on one, others will need the same maintenance shortly.

Baldwin, in the northeast corner of Sherburne County north of the Twin Cities, sees this coming from 20 years away and is trying to find a way to afford its road infrastructure. In its 2010-2015 Capital Improvements Plan, Baldwin splits its road costs into two categories: maintenance and capital improvements. The plan states that Baldwin will likely need a 6 percent increase per year in maintenance costs to roads -- to continue the kinds of processes that increase a paved road's life, such as chip sealing -- and a 20 percent increase per year in capital improvement costs -- the larger, more expensive projects, such as reconstruction and overlay -- for some time to come.

It further concludes that costs will only increase if these repairs are delayed because the township is unable to raise enough funds.

But if the township can't afford upkeep on all of these roads, what are its other options? What if it returned some of the roads to gravel? It's a question getting increasing attention as local governments find themselves under stress. And, in fact, what at first glance seems short-sighted, in Baldwin Township might save money in the long run.

Stutsman County, N.D. recently decided to return roads to gravel in order to be able to afford its infrastructure, and they aren't alone.

As the Wall Street Journal article states: "In Michigan, at least 38 of the 83 counties have converted some asphalt roads to gravel in recent years. Last year, South Dakota turned at least 100 miles of asphalt road surfaces to gravel. Counties in Alabama and Pennsylvania have begun downgrading asphalt roads to cheaper chip-and-seal road, also known as 'poor man's pavement.' Some counties in Ohio are simply letting roads erode to gravel."

But how feasible is this process?

Sherburne County's road maintenance figures show that costs to keep up gravel roads far outweigh those to keep up bituminous. From 2005 to 2009 the county spent $43,411.23 in maintenance costs on just over 23 miles of gravel county roads. But over the same period of the time the county only spent $27,293.13 in maintenance costs on 2,028.6 miles of paved road. Using those figures, it cost the county about $1,887.44 per mile of gravel road that needed maintenance and about $13.45 per mile for maintenance on bituminous.

The yearly maintenance costs of gravel roads make them appear inefficient, until you consider the capital improvement costs associated with bituminous roads at the middle and end of their lives, which isn't always reflected in yearly maintenance figures.

Baldwin's own cost estimates for maintenance over the next five years illustrate the hidden costs of paved roads. In 2010, reconstruction of 0.128 miles along 99 1/2 St. cost $49,863 dollars, or $389,554.69 per mile. In 2011, reclaim/overlay of 289th and 127th streets for 0.7 miles will cost $43,659, or $62,370 per mile. In 2012, reclaim/overlay of 0.7 miles along 100th St. will cost $97,241, or $138,951.71 per mile. In 2013, overlaying a mile of bituminous on 112th St. will cost $99,915.

While bituminous overlay only needs to be done to roads 20 years after they are built and reclaim/overlay 40 years after they are built, these high costs are hard for townships to absorb all at once, even when they plan for them years in advance.

Over its 40-year lifespan, a low-volume paved road will need to be chip sealed twice, undergo overlay once and then reclaim/overlay. Baldwin's 2010 estimate to chip seal paved road is $3,885 a mile. Cost for capital improvements is obviously dependent on the condition of a road. As the figures above show, these can vary significantly.

Using a weighted average of the above figures, the reclaim/overlay costs are approximately $124,844.90 per mile of paved road. Adding the chip seal costs twice, the estimated overlay cost from the above figures ($99,915) and the reclaim/overlay cost, Baldwin's paved roads will cost an estimated $232,529.90 per mile every 40 years, or $5,813.25 per mile per year.

That's about 3 times what it costs to maintain gravel roads in the county.

As the Wall Street journal said, paved roads were once a hallmark of the United States. With this mentality, it is hard to let go of paved roads, but maybe it's something Baldwin needs to consider. Letting some roads return to gravel at the end of their 40 year lifespan could help Baldwin afford the paved roads it needs while keeping taxes manageable for all residents.

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