Why Does Hwy N Look Oily? Why Doesn’t All of Hwy 12 Look New? [Updated]

By Lynn Binnie
Whitewater Banner volunteer staff
whitewaterbanner@gmail.com

Updated 11/14/23 @ 3:15 p.m. to show a response at the bottom of the article from the state project manager regarding the sealer that the county used on their project.

County Highway N

Readers may have noticed areas on the newly resurfaced County Highway N that look oily or shiny. Some people have even expressed the opinion that the road is slippery when wet or cold. The Banner reached out to Duane M. Jorgenson, Jr., director of public works for Rock County, to inquire about these reports. His response is shown below.

“We applied a thin asphaltic emulsion sealer on CTH N (similar to a couple other county highways in the past couple years).  This is a treatment to fill in small air voids in the surface material to reduce the early deterioration of the pavement in an effort to extend the life of the pavement.  (Typical life expectancy is approx. 24 years; we are trying to extend it to 30 years).  These small air voids get water in them and with the freeze thaw cycles we see and combination of the pavement oxidizing over time (you see the pavement turn lighter gray over time) the pavement begins to break down.  This is an effort to slow that deterioration process down.

The sealer does leave a slight sheen appearance initially, but that will wear off in time.  There should not be any significant difference in slipperiness as compared to a new asphalt pavement.  We did some friction testing on a section last year and it was consistent with new pavement.”

US Highway 12

Upon the long-awaited reopening of Highway 12 between Whitewater and Fort Atkinson, some people expressed great relief but questioned why not all the pavement looked new. The Banner reached out regarding this to Craig Hardy, the project manager for the Wisconsin Department of Transportation.

Per Hardy, resurfacing of Highway 12 took place in three phases over the past five years:
– Whitewater Bypass intersection with Business Highway 12 to Buckingham Road started on 4/12/18 and was completed on 9/28/18.
– Buckingham Road to south of Star School/Carnes started 3/6/23 and was completed the week of July 4th.
– Star School/Carnes to County Highway M started 7/6/23 and was completed 11/3/23.

Hardy stated, “When asphalt is placed, all of the oils on the surface are fresh and give off the “new pavement” look. When the southern sections of asphalt were originally placed, it was just as black as the new pavement on the northern half. Over a short period, the sun, dirt and dust have a “bleaching” effect that lightens the color of the pavement. In a few months the northern half of the project will have a similar grey look like that of the south half of the project.”

Update: Reader Eric Cutshall inquired as to why the sealant used on CRH N wouldn’t have also been used on US Highway 12. Hardy provided this response to the Banner, “WisDOT doesn’t typically use the emulsion sealer on our projects. It is a tool that entities can use in their proposed pavement life cycles, but not a requirement. As technologies improve, and studies are completed, maintenance strategies change from organization to organization. As this time we do not use it as a standard practice.”

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