Provincial tests show Red Hill friction levels declined but were still 'acceptable'

The data was collected from lanes along a four kilometre stretch between 2007 and 2014 as part of an evaluation of the stone used in the asphalt for potential use in future ministry projects.

Minister ordered tests be released after bombshell city report was buried

Provincial tests on the Red Hill Valley Parkway show its friction levels declined over time, but a ministry spokesperson says that's typical. (Dan Taekema/CBC)

Testing completed by Ontario's Ministry of Transportation on a stretch of the Red Hill Valley Parkway showed the road's friction levels declined over time, but were still deemed "acceptable."

It's a rating that meant the stone used in its asphalt was added to a list of approved sources for Ontario roads.

The provincial test results are the latest chapter in the debate about the road's safety after it was revealed the city had done testing that raised concerns about the pavement.

The provincial data was collected from lanes along a four kilometre stretch from Greenhill Avenue and a rail bridge between 2007 and 2014 as part of an evaluation of the stone in the asphalt for potential use in future ministry projects, according to spokesperson Bob Nichols.

"The results were within our acceptable range and the aggregate was placed on our list of approved sources," he explained.

Transportation Minister Jeff Yurek ordered the tests be released following a bombshell announcement last week that a 2013 friction test for the deadly parkway was buried. 

That report by Tradewind Scientific found friction levels along Red Hill were below expected standards — and in some places, well below. 

Hamilton city council is meeting Wednesday night to debate whether to make all of its reports about the parkway public tonight, and to determine if an outside investigation into how a report remained hidden so long should be launched.

Downward trend 'typical'

Nichols said the ministry never compiled a formal report.

Instead, after the minister's request, staff release four charts broken down by lane.

This chart shows the province's friction testing for one of the northbound lanes of the Red Hill Valley Parkway. (Ministry of Transportation)

The ministry started collecting data for the southbound lanes in 2007, with collection for the northbound lanes starting the following year.

Staff noted friction levels for pavement tend to be lower in its first year until a "thin film of asphalt cement wears off." Typically, the friction improves in the second year, before starting to trend slowly downward.

"The data shows that the pavement friction trends slowly downwards over time, as might be expected as a pavement is exposed to traffic wear over the years," said Nichols. "The numbers are typical as they started out higher but started to slowly decline over time."