Milling on Hunter Avenue at Killoren Crescent Thursday. 250News photos

Prince George, B.C. – The City’s 2015 road rehabilitation projects are underway with the first seven jobs on the list to be completed, weather permitting, by next Thursday, May 14^th.

A good portion of the 2014 road work concentrated on getting the main routes and thoroughfares done in advance of the city hosting the 2015 Canada Winter Games the last two weeks of February.  That meant many of the streets in residential and secondary areas were left off the list last year and are being rehabilitated this year.

Crews working for Pittman on this year’s projects have made an interesting discovery, one acknowledged by City Hall.  And that is that the cap above the road bed on some of these streets is, in some cases, drastically below the thickness dictated by today’s standard.  As an example, it has been pointed out that the cap on certain spots on Killoren Crescent in the Heritage area is perhaps 30 to 35 millimetres thick when the standard now is about 65 millimetres.

The Supervisor of Streets Operations with the City, Mick Jones, says “you are correct and I don’t have an answer for it, I can’t explain it, I don’t know why, but when we get onto some of these older roads we find that they are not even close to what should be there.  And after they did Killoren they went down to Ewert and we found less than an inch of asphalt in spots.”

Jones says “the City’s minimum standard on a local road is 65 millimetres.  On arterial and collectors it can be anywhere between 75 and 100.  So on 15^th and Ospika and all the major roads we don’t run into these problems usually because there’s lots of asphalt there.  But a lot of these residential streets, for whatever reason, I don’t know what it was, I don’t know if it was just a lack of volume control, I have no idea.”

“But we find that more often than not on the side streets where we blow through.  Like where we do the milling we try to remove enough so that it can bite into the curb and then we’ve got enough but we’re trying to add more structure at the same time.  Because we’re always finding on some of these side roads that there’s not enough there and maybe that’s why they’re in such poor condition, because there’s not enough there, so we always try to add more.”

Jones says “the whole point of the milling is to remove as much of the asphalt distresses that we can, but knowing that there’s probably not as much mix as there should be on some of these side roads we just try to do the edges and then overlay and put more on, just so we have more road structure.”

That slows deterioration and, says Jones, “basically it increases the grade of the roads so that the water gets into the gutters better.  That’s the biggest thing, water on the roads contributes to a lot of the problems so if we can get the water to the gutters, we’re better off.  But it is not uncommon to find less than our current standard on some of these older roads.”

Paving of Killoren, between Hunter and 5th Avenue, began Friday morning

He says this discovery won’t affect or prolong the road rehab schedule for the year.    He adds, “the biggest challenge is we go in with a plan and a budget for that plan and then when we run into gravel we put more asphalt back to make sure we’re getting close to our standard.  But at the same time, if the project was estimated to go in and put 50 mills of asphalt, where we blow through and try to add some it puts us closer to budget.”  Jones adds that there is not a threat of going over budget “because each budget has a contingency, so then we end up using the contingencies on these sorts of issues.”

“So it’s not the end of the world, it’s just more frustrating.  I don’t know what happened back then, that was before my time and you just don’t know how some of the stuff was done the way that it was back then.”  He says it may have to do with lower standards in the past.  “That’s part of it but also I don’t think there ever would have been a standard of an inch of asphalt.  So I don’t know how it would have been acceptable.”

Jones reiterates that 65 millimetres is the minimum asphalt thickness on a local road within the city of Prince George but adds “on any project where we’re working off gravel we go with at least 75, just for a little extra.  It costs a little bit more but in the end more asphalt is better to increase road structure.”

“If we’re just doing an overlay on existing asphalt, we’ll go as thin as 40 millimetres and we’re still adding road structure to what’s there.  But usually on the ones where we’re doing milling, like a straight mill like we did on Foothills, we put back exactly what we take off.  Grind off 50 millimetres, put 50 back.  That’s most common on the roads where there are islands because then you’ve got a gutter on both sides.”

Paving Killoren was completed early Friday afternoon

“Like on Killoren Crescent, because it’s just a road with gutters on both sides, we can mill the curb edges and then we put more asphalt back, it creates a little steeper slope to the gutters.  You’re building it up more in the middle than you are on the edges and all it does is get the water to the gutter quicker.  It doesn’t create a challenge to traffic or anything like that.”

The City is spending $7 million on 51 road resurfacing and 16 sidewalk rehabilitation projects in 2015.