Upcoming Webinar

If you are interested in work zone data collection and analysis, I suggest you register soon for a webinar put on by ATSSA and led by Brian Chandler of SAIC entitled, “WZ Safety Data Collection and Analysis”. For more information or to register click here:  The Work Zone Safety Data Collection and Analysis Guide Promo

Queue Warning Systems

You are probably familiar with the term “low hanging fruit”. It refers to the easy items on your to-do list – those you can complete with very little effort and which are almost certain of success. In the world of work zone ITS the item at the top of everyone’s list of low hanging fruit should be queue warning systems. I say this for several reasons:

  1. The technology is proven, mature, and available everywhere.
  2. It is easy to use, and easy to maintain.
  3. These systems cost very little.
  4. The benefits are HUGE! 26% of all work zone fatalities occur as a result of end of queue crashes. Any measureable reduction will put a big dent in a state’s work zone fatality numbers.

Many states already recognize this and are requiring these systems for any project where dynamic queuing is anticipated. They don’t have to be major projects. In fact, queue warning benefits small to midsize overlay projects more than any other. There the queues are unpredictable. The job location moves daily so even the locals are often surprised by it.

These systems consist of one or more traffic sensors upstream of the work. Usually these are spaced a half mile to a mile apart. In rural areas that spacing might be increased. The sensors send the data in real time to a server. When slow or stopped traffic is detected, the server triggers a warning on one or more portable changeable message signs further upstream. All of that takes place in seconds.

Drivers pay attention when you tell them SLOW TRAFFIC AHEAD / PREPARE TO STOP. And if they drive that route regularly they will soon appreciate the timeliness of the warnings.

If you decide to use them in your state, there are a few things I recommend:

  1. Always place the first message sign (the one farthest from the job) well upstream of any potential queuing. You don’t want the traffic to back up beyond that sign.
  2. Most systems accommodate three sets of messages: a standard, free-flow message (CAUTION / ROAD WORK AHEAD); a slow traffic message (SLOW TRAFFIC AHEAD / PREPARE TO STOP); and a stopped traffic message (TRAFFIC STOPPED AHEAD / PREPARE TO STOP). For freeways and highways posted at 55 MPH or higher, try setting the trigger speed at 45 MPH for the slow traffic message and at 25 MPH for the stopped traffic message. These are average speeds so one slow tractor won’t normally trigger the warnings.
  3. Watch the results. You may need to adjust the trigger speeds, or the sensor spacing, or the message sign spacing. No two jobs are alike, but you will quickly learn what works best in each situation.

Sensors rent for no more than message signs in most cases. So a system like this will cost no more than twice what you were already planning to spend for “dumb” message boards and it will be far more effective. Queue warning systems are proven to significantly reduce both the number and severity of rear end crashes. ..that’s low hanging fruit for sure!

The Importance of Networks

I hope you will excuse this commercial interruption but this blog was started to facilitate the discussion of and, we hope, speed the development of work zone and rural ITS. In this month’s issue of Wired magazine you will find an article entitled, “Thinking Out Loud – How Successful Networks Nurture Good Ideas.” It talks about the importance of open discussion to innovation.

When we learn how others are using technology it often leads to ideas of our own. If a new widget can do X in one industry why couldn’t it be used to do Y in ours?

I understand my readers’ need for anonymity so I also understand why we get so few public comments. But please keep them coming through back channels. If we aren’t talking we aren’t saving as many lives on our roads as we could.