The calendar says winter, but the work continues on in King County as crews mark the beginning of a new construction year.

While crews are able to make the most progress with weather-dependent work during the summer months, more and more construction work is being done in the off-season for a number of reasons.

For instance, technology and ingenuity has allowed King County Road Services crews to work year-round on some of their largest and most complex projects.

"We still don’t do major grading and big-equipment work in the winter, but on the larger, multi-phase projects there are many things that can be accomplished – if we do good advance planning," said Matt Nolan, a managing engineer for the Roads Division.

Northeast 124th Street near Redmond and 140th Avenue Southeast east of Renton are two big projects that are currently continuing construction during the wintry weather. The construction cost for each is approximately $8.2 million.

The 124^th Street project – which is Phase 2B of an even larger overall project – is still in the early stages. In the past several weeks, crews have been building retaining walls and adding fill dirt along the south side of the road in preparation for widening. The expanded roadway between State Route 202 and Willows Road will be paved during the summer months, and construction should be complete next fall.

The 140^th Avenue project is also one phase of a larger job that stretches from State Route 169 to Southeast 197th Street. In this case, most of the widening work is completed, but crews are building retaining walls, and preparing to install curbs and sidewalks. As with 124^th Street, the new asphalt will have to wait for warmer weather.

"The biggest change over the years is that we can now do more soil work in the winter months," said Nolan. "We do a better job of stabilizing soil to prevent runoff and erosion, and to improve workplace safety. We know how to adjust for the weather."

He said technology now gives construction crews a lot more information about the soils that they are working with – both those on-site and the ones trucked in for the job. Nolan says every type of soil has an optimal moisture level for construction work – the trick is knowing how and when to add or subtract moisture.

"We actually track the moisture level of each load of dirt as it moves from our shop yards to our job sites, and even on a daily basis once it is out at the site," said Nolan.

The goal is to have stable soil – no matter what the weather – to make sure the erosion control is working to protect the environment and the workers, and to avoid stop-work orders that would delay project completion.

The advanced erosion-control techniques also lets the division accomplish some types of clearing and small-scale grading work in the winter, such as the current projects near the Edgewick Bridge and along 124th Avenue Northeast in Kingsgate (see below). Working with improved materials and modern-day equipment, crews are currently installing curbs and sidewalks along Military Road and at a few other sites in the unincorporated areas.

"Forty years ago, road construction crews had to be laid off during the winter and projects took much longer to complete," said Nolan. "Today’s technology and advanced knowledge can keep projects humming on a year-round basis."