Road Rating and Maintenance
The City of Madison rates all streets every two years for condition. The City uses a 1-10 scale to rate pavement, curb and gutter. A new street has a rating of 10. After street rating, the City works to decide the best route to improve the street and increase its longevity before having to replace the entire street all together.
Four stages of preventive maintenance are completed on City of Madison streets progressing from Crack Sealing, to Chip Sealing, then Resurfacing, and finally Reconstruction.
Street Rating Scale
Seven or Above Rating: Crack sealing (Crack sealing pavements is done at five and 10 years of age.)
The cracks in the street are cleaned of debris and are filled with a sealant. By sealing cracks, it prevents surface water from penetrating into the pavement foundation, and the spread of cracks in the pavement. Crack sealing includes the following process: removing debris, applying rubberized asphalt and applying tape to hot crack sealant. The tape prevents hot tar from splashing onto vehicles.
Five or above Rating: Chip sealing is typically done every five years after the second round of crack sealing.
Chip Sealing has been used by the City of Madison as a cost effective way to maintain unimproved streets. The City of Madison began using Chip Sealing on improved streets with curb and gutter and an asphaltic pavement in 2006. Chip Sealing is typically done every 5 years after the second crack seal. Chip seal is an application of a binder in the form of an emulsion (asphalt and water) and an application of an aggregate (chips), which is used to keep the water out of the pavement.
Chip Sealing includes the following process: applying asphalt emulsion and chips (Black Boiler Slag) on the street, rolling and compacting the chips and sweeping of loose debris. The road may be open to traffic before sweeping 24-48 hours later.
4-6 Rating: Resurfacing
Resurfacing typically includes placing a new layer of asphalt over the existing pavement. Pavement in very poor condition is pulverized prior to a new surface being placed. The process of resurfacing includes the following process: pulverizing existing pavement, completing pavement operation, rolling to compact the pavement.
Three-Five Rating: Reconstruction, this includes when curb and gutter is rated between 3-5
Once City Engineering rates a curb and street of 5 or below, then the street is considered for reconstruction. A street is generally reconstructed every 30-40 years, based on the street rating.