Navigating Through Construction Zone Signs

Q: Are there any requirements for the use and/or placement of signage to warn drivers when construction affects the flow of traffic? Who is responsible for setting up the signs?

A: Oh yes, there are requirements. Pages and pages of requirements. The Manual on Uniform Traffic Control Devices (MUTCD), which Washington has adopted as its rule book for signs, signals, road markings has nearly 200 pages devoted to what it calls Temporary Traffic Control (TTC). That’s the official term for signs used during construction or other scenarios that require a short-term change in traffic patterns, such as a crash that blocks traffic or a truckload of salmon that spills onto the highway.

Road construction presents unique driving challenges; the change to the roadway is unfamiliar, during construction we’re driving in conditions that are sometimes below the normal standard of the road we’re on, and the routes at times travel precipitously close to construction workers. For those reasons, it’s critical that construction zones are clearly marked, so it’s no surprise that we have rules specifying how to provide signage in construction zones. Don’t worry, we’re not going to cover all the rules. Instead, we’ll look at the motivation behind the rules.

The goal of temporary traffic control is to protect people on the construction site, keep road users safe (including drivers, cyclists and pedestrians), and move travelers through the construction zone as efficiently as possible. To do this, the MUTCD bases its guidance on seven fundamental principles of temporarily traffic control. I’m only going to mention the first three:

1. Safety – I’ve already said it, but it’s worth repeating. TTC should protect road users, workers, emergency responders and anyone else inside the construction zone.

2. Road user movement should be “inhibited as little as practical”. The MUTCD discourages significant deviations from the original route, lots of abrupt changes and dramatic speed decreases, as it increases difficulty for motorists navigating construction zones.

3. Road users should be guided in a “clear and positive manner” through the construction zone. We want to have signs that leave no confusion for drivers.

By following those principles, TTC planners do their best to develop routes that are safe, change as little as possible and are clearly marked. But who are these TTC planners? Temporary traffic control is approved by the government agency responsible for the roadway; for example, on a construction project that affects drivers on a county road, traffic engineers at Whatcom County Public Works would review and approve the plan. That doesn’t mean that county traffic engineers would always develop the TTC plan. TTC plan development and implementation is the responsibility of whoever is doing the work. Often on road projects, a private company contracts with local government to do the project. In this situation, the construction company would submit a TTC plan to local government. The plan would be reviewed to make sure it meets safety requirements and doesn’t conflict with other construction projects. We don’t want to have a TTC plan that includes a detour onto a road that has just been closed by a different construction project. Once the plan is approved, the contractor would be responsible for implementing the plan and making sure that throughout the construction project the traffic control on site meets the plan requirements.

In reviewing the MUTCD guidance on temporary traffic control, I have one concern. The MUTCD is possibly overly optimistic when it states: “. . . road users are assumed to be using caution . . .” We’ve all seen situations where that is not the case. Let’s all do our best to prove the MUTCD right every time we drive, ride or walk through a construction zone.

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