Street Fight, Part 1: Roads Take a Beating | News

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Street Fight, Part 1: Roads Take a Beating

The Ongoing Battle for Better Bay Area Pavement
Street Fight
Tuesday, October 28, 2014

The Bay Area’s local streets and roads are a priceless asset, essential to the region’s livability and economic health. Comprising more than 48,000 lane miles of roadway — and not just the paved surfaces but also the curbs and gutters, sidewalks, storm drains, traffic signs, signals and lights that are necessary for functioning roadways — the local street and road network provides access to jobs, homes, schools, shopping and recreation for motorists, bicyclists and pedestrians alike. Yet the condition of this asset is fair at best and its future is precarious.

The typical stretch of Bay Area asphalt shows serious wear and likely will require rehabilitation soon. At 66 out of a possible 100 points, the region’s average pavement condition index (PCI) score is much closer to the 60-point threshold at which deterioration accelerates rapidly and the need for major rehabilitation becomes much more likely than to the 75-point score that MTC has established as a target for roadway quality. Indeed, despite efforts by the Commission and the region’s local governments, the Bay Area's battle against potholes has at best been fought to a draw: overall conditions on city streets and county roads essentially are the same now as they were in 2001.

Very Good-Excellent
(PCI = 80-100)
Newly constructed for resurfaced pavement with few signs of distress.
(PCI = 70-79)
Pavement requiring mostly preventive maintenance and showing only low levels of distress.
(PCI = 60-69)
Pavement at the low end of this range is significantly distressed and may require a combination of rehabilitation and preventive maintenance.
At Risk
(PCI = 50-59)
Deteriorated pavement requiring immediate attention, including rehabilitative work.
(PCI = 25-49)
Pavement showing extensive distress and requiring major rehabilitation or reconstruction.
(PCI = 0-24)
Extremely rough pavement that needs complete reconstruction.

To achieve the goal of a local street and road network that's solidly in the “good” category, Bay Area cities and counties must accommodate myriad — and sometimes competing — priorities, and overcome enduring challenges that are both physical and fiscal.

The physical challenges are quite simple: streets and roads take a beating under the weight of traffic. Not surprisingly, heavy vehicles such as trucks and buses put more stress on pavement than does a passenger car, with this additional stress exacerbated by frequent stopping and starting. What may be surprising, however, is just how much bigger the impact of heavier vehicles really is. A delivery truck exerts more than 400 times the stress on pavement than does a typical sport utility vehicle, while a garbage truck exerts more than 9,000 times as much stress as an SUV. This illustrates the competing priorities that often must be considered in the battle for better pavement. No matter how important the goal of a smooth ride may be, the sacrifice of either curbside waste collection or convenient and reliable transit service at the altar of perfect asphalt is not a viable policy option.

bar graph displaing relative impact of vehicle types on pavement conditions

Cracking usually is the first sign of distress on any surface pavement. While cracks may not immediately alter the pavement’s ride quality, they expose the sub-base of the roadway to water leaking through the surface layer. In time, water erodes pavement strength and cracks begin to lengthen and multiply, forming networks of interconnected cracks referred to as “alligator cracking.” At this point, the pavement is no longer able to sustain the weight of traffic and the cracked pavement disintegrates, forming depressions more familiarly known as potholes.

Since potholes result from damage to the roadway’s sub-base, once they appear — regardless of whether or not they are patched — the roadway will continue to deteriorate until it reaches a failed state. Predictably, cracks appear more quickly on streets with large traffic volumes and/or heavy use by trucks and buses; and these roadways need maintenance more frequently than residential streets with comparatively light vehicle traffic. About 28 percent of the Bay Area’s local street and road mileage consists of arterial and collector roadways, which are heavily used by both trucks and buses.

The pounding that pavement receives from trucks and buses can be especially problematic in more rural parts of the Bay Area, where many roadways have not been designed to accommodate heavy vehicles but which are nonetheless used by growing numbers of trucks carrying goods between farms and cities. A 2014 report by The Road Information Project, or TRIP, a nonprofit organization that researches, evaluates and distributes technical data on transportation issues, estimates that 49 percent of Bay Area roadways — including state highways as well as local streets and roads — are in poor condition.

View the complete list of 2014 PCI scores.

Continue reading: part 2, The Fiscal Challenge

We have many local roads and highways that need a lot of maintanance. It's a never ending cycle of repair, and Vitals Signs shows us exactly how well we're doing in some areas as well as those that need more attention.

A 2014 report by The Road Information Project, or TRIP, a nonprofit organization that researches, evaluates and distributes technical data on transportation issues, estimates that 49 percent of Bay Area roadways — including state highways as well as local streets and roads — are in poor condition. "Approximately $800 a year is spent by Bay Area motorists maintaining their vehicles," says Rocky Moretti of TRIP. "These are additional costs that they're paying because of the rough roads in the region.

Like the rest of the Bay Area's transportation network, the region's local streets and roads are showing their age while carrying heavier loads. "Our cities and counties face a double whammy of challenges," explains Hans Larsen, Transportation Director for the City of San Jose. "We're in a region where things are growing fast, and there's a need to invest in transportation to support growth. At the same time, we have transportation systems, many of them built 50 or more years ago, that are aging and falling apart, and need investment. There are not enough dollars today to deal with either growth or maintaining what we have."

Local Streets and Roads by the Numbers

Total Lane Miles: 42,86

Replacement Value: $39 Billion

Excellent Condition: 9%

Very Good Condition: 23%

Good Condition: 21%

Fair Condition: 13%

"At Risk" ConditionL 10%

Poor Condition: 16%

Failed Condition: 7%


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