New Approaches for Urgently Needed Road Maintenance
Souri Amirani is deputy city engineer for the City of Santa Ana’s Public Works Department and can be reached at firstname.lastname@example.org .
Finding ways to deal with crumbling roadways is a concern for cities statewide. Years of deferred maintenance due to state funding shortfalls have resulted in a backlog of streets that need repairs, compounded by an ongoing scarcity of revenues to pay for fixing roads.
One city is meeting the challenge of urgently needed road maintenance by using new technology and an innovative approach to funding street improvements. The City of Santa Ana (population 353,000) covers 27 square miles with more than 400 miles of roads to maintain. In 1991, the city began using pavement management software to effectively manage the maintenance of its aging street network. To determine the pavement condition of all its streets, the city performed a field inventory for its 112 miles of arterial streets and 311 miles of local roads. The inventory has been updated every two years since its implementation in 1991.
To qualify for grant funding from the Orange County Transportation Authority (OCTA), the city is required to maintain the pavement management program. Santa Ana has been very aggressive in obtaining grant funding for arterial streets through OCTA. With the funding obtained and the local match, the city has been able to maintain a pavement condition index (PCI) of more than 80 on a scale of zero to 100 for the arterial network.
However, Santa Ana has not had a reliable funding source for local residential streets to meet the ever-increasing maintenance backlog. Projects were traditionally funded on a "worst streets first" basis. Only the worst streets requiring total reconstruction and the highest construction costs were considered, and citizen complaints were also taken into account in prioritizing needed repairs. Based on the $1.5 million historically committed to these streets, bringing the entire network up to a condition that was maintainable appeared insurmountable. The city needed an alternative to its traditional funding strategy.
In 2007, the city’s maintenance backlog for neighborhood streets topped $350 million, with an average PCI of less than 45. In order to make a large dent in the backlog and halt declining pavement conditions, the city had to find a new source of funding.
Options considered included assessment districts and bonds. The assessment district option was eliminated due to lack of public support. The bond option appeared viable, because the city was considering a Certificate of Participation (COP), which doesn’t require voter approval if approved by the city council. Unlike a general obligation bond, which is a loan taken out by a city against the value of taxable property in the locality, a COP is a tax-exempt lease obligation. The investor buys a share of the lease revenues of an agreement made by a municipal or governmental entity, rather than the bond being secured by those revenues. COPs pay tax-exempt interest and enjoy the liquidity of a marketable security similar to a municipal bond.
After extensive financial analysis, a $60 million COP was determined to be affordable, and Project Restore --- the new street improvement program --- was launched in 2007.
A New Approach
Project Restore departs from the city’s standard methodology of funding and implementing projects in several ways. First, the project funding comes from several traditional sources, including $40 million of Community Development Block Grant, local revenue Measure M, Proposition 42 and Prop. 1B funds. By leveraging this money to obtain the $60 million COP, the city was able to fund a program that invests $100 million in the neighborhood street network citywide over five years. The goal is to reduce the maintenance backlog to a point where existing funding streams could be used to cover it.
Second, Project Restore uses a "best streets first" philosophy. One tenet of pavement management is that the older the street section, the more extensive and expensive the required maintenance activities. By focusing on the better streets first, the city is maximizing the funding available to protect these streets at their current levels, rather than fixing the worst streets while allowing the best to continue to deterio rate. In the program’s first year, a thin overlay of asphalt is applied on 64 miles of streets. In following years, more invasive and costly techniques will be used.
Third, improvements are based on the greatest need, ignoring neighborhood boundaries. Historically, projects were neighborhood specific, which meant it could take many years to reach some of the city’s 60 neighborhoods. By spreading the work citywide and basing it on pave ment condition, all areas are improved simultaneously. This demonstrates to residents that the city is committed to repairing the streets in a fair manner.
Fourth, the program uses a "specifications only" bid package. Typically, street projects put out to bid include a set of plans detailing all the improvements. Preparing these plans is labor intensive and time consuming. Instead, design staff focused on cataloging all necessary improvements and presenting them in tables in the specification. Design staff also supports the construction inspector in laying out proposed improvements in the field. By eliminating the plans, the design effort is reduced. This saves on design costs, and these savings are applied to construction. The reduced design effort also gets projects under way more quickly and efficiently.
Cheaper, Environmentally Friendly Alternatives
Finally, Santa Ana is using alternative strategies to maintain the streets. Previously, the city used only slurry seal, thin overlay and total reconstruction. The assumptions made in the inventory report were based on these conventional con struction techniques. As the price of building materials, including asphalt, continued to rise, alternative strategies were necessary t o maximize available funds. Staff investigated several environmentally friendly, alternative maintenance/rehabilitation techniques to reduce construction costs and associated waste materials.
One solution, cold in-place recycling (CIR), shows promise in its ability to rehabilitate existing pavement at a greatly reduced cost. The process involves grinding off the existing pavement, treating it with a recycling agent and laying it as new pavement, then sealing it with a thin layer of new asphalt. The existing asphalt is recycled in place, which reduces the cost of hauling and disposal. It also cuts the greenhouse gas (GHG) emissions from this hauling. According to several studies conducted by Canada’s Ontario Ministry of Transportation, CIR uses up to 80 percent less energy compared to traditional hot mix asphalt with roughly half the carbon dioxide and nitrogen oxide emissions and approximately one-third the sulfur dioxide emissions. For a given length of street, CIR emits approximately 50 percent less GHGs, consumes 62 percent less aggregate and costs 40 to 50 percent less than conventional mill and overlay treatment. Santa Ana used CIR with great success in the recently completed Delhi Neighborhood Improvement Project.
Santa Ana recently began using another pavement rehabilitation process, cement-treated base (CTB), more extensively. The CTB process involves pulverizing the existing pavement, mixing it with existing base material and adding cement. This becomes the base layer for new asphalt pavement. While not as cost effective as CIR, CTB is less expensive than full-depth conventional pavement reconstruction. Recent successes on arterial street projects convinced staff that this treatment provides a cost-effective method for repairing neighborhood streets in the worst condition.
Project Restore offers a model for leveraging public works dollars, cutting costs, improving efficiency and finding more environmentally friendly ways to serve the community.
Warm-Mix Asphalt: Enviro-Friendly and Durable?
by Jennifer Whiting
Jennifer Whiting is a legislative representative for the League and can be reached at email@example.com.
Cities are always looking for creative ways to meet environmental standards, but balancing enviro-friendliness and durability can be tricky. Fortunately, new technologies are being developed to help meet municipal needs.
Warm-mix asphalt is a good example of such new technology, and it’s generating intense interest. After being used for 10 years throughout Europe, warm-mix asphalt was introduced in the United States after a 2002 study tour by the National Asphalt Pavement Association. While some state and local governments are considering the possibility of using this new product on a widespread basis, there are many who still don’t know much about it.
Producers of pavement material have been able to mix and place warm-mix asphalt on the road at lower temperatures than those used for hot-mix asphalt, with documented reductions of 50-100 degrees Fahrenheit. The benefits of mixing and placing asphalt at lower temperatures include cutting fuel consumption by as much as 40-60 percent and decreasing the produc tion of greenhouse gases. In addition, lowering the production temperature reduces emission production by 80-97 percent, improving conditions for workers and surrounding communities.
Unlike many developing technologies, warm-mix asphalt can be used with existing processing equipment, allowing cities to use their limited funds on the actual projects rather than on new equipment.
The long-term durability of warm-mix asphalt has not been proven in the United States, but tests are under way in several states, including California. In September 2006, the City of Escondido contracted for a new 12,000-square-foot parking lot using 250 tons of warm-mix asphalt, and in October 2007, a residential paving project using warm-mix asphalt was completed in Stockton. More such paving projects are in the works. The California Department of Transportation’s (Caltrans) District 5 hosted a Warm-Mix Asphalt Innovation Project in May 2008 in Morro Bay and San Luis Obispo. The University of California, Davis, is also working with Caltrans to test the durability of warm-mix asphalt in Watsonville.
Warm-mix asphalt has been tested in several other states with positive results. Logan International Airport in Boston, Mass., recently announced that it would be using warm-mix asphalt on a runway repaving project. The project is expected to reduce carbon emissions by nearly 2,000 pounds, save about 200,000 gallons of diesel fuel and produce an energy savings of about 26.4 billion BTUs. Airport authorities decided to use warm-mix asphalt after testing it on a taxiway and apron areas with oversight by the Federal Aviation Administration. In addition to the environmental benefits and improved working conditions, the airport found that warm-mix asphalt compacts better, allowing for sturdy runways that can withstand the impact of heavy airplanes and high-pressure tires.
As cities continue to look for new ways to meet environmental standards, warm-mix asphalt may offer a promising alternative.
Saving on Signage in Pleasanton
Gordon Cordova runs one of the most productive municipal sign shops in California. For more than 35 years, the City of Pleasanton has had a sign-making function, which has evolved into a state-of-the-art shop.
With more than 100,000 signs throughout Pleasanton, Cordova and his staff of five have plenty to do. In addition to producing and installing all of the municipal signs, they also manage graffiti abatement; provide signage for special events, road closings, detours and traffic diversions; and are responsible for all roadway markings, curb painting and most of the city’s thermoplastic street striping.
This busy group turns out 10 to 20 traffic signs per day on average, saving Pleasanton 60 to 70 percent of the manufactured cost for each sign. For example, a standard stop sign ordered through a manufacturer can cost $185 to $220. Cordova’s shop produces the same sign for $70 to $75 and can have it made in 10 minutes, a significant benefit when roadway accidents destroy critically important signage.
Pleasanton ’s sign shop can produce 50 double-sided street name signs a day for 50 percent less than it would cost to purchase them from a manufacturer. This makes it much easier to comply with the 1997 California state mandate to have all street signs display letters that are at least six inches high. Thanks to Cordova and his crew, Pleasanton has produced 2,200 of the new street signs and has just 1,500 to go by the January 2012 deadline.