The in basket: Tom Baker of the city of Bremerton electronic shop e-mailed me on July 24 to say, “I happened to be in Bellevue during the I-90 lane closures, and paid a bit more attention to the WSDOT Traffic Map on my Android phone. When stopped in traffic, I noted the traffic flow was very close to what was shown as Red-Yellow-Green.
“I then I looked at the traffic map for Kitsap County/ Bremerton at about 9 p.m. and currently shows red along Kitsap Way eastbound by Oyster Bay and some red along Callow Avenue.
“WSDOT uses sensors to determine the average speed. What are the sensors and how do they work for the I-5, 405, etc. highways?
“How is the traffic map updated for Kitsap County/Bremerton?”
The out basket: Tom’s question caught me entirely by surprise, as I didn’t think there was any such real-time information available online for West Sound highways north of Gig Harbor.
The state provides online maps showing traffic flow in green (good), yellow (slow), red (even slower) and, on some maps, black (probably stopped) in the Seattle and Tacoma areas. We see them all the time on the TV news. But the information for Highway 16 ends at Gig Harbor.
Imagine my surprise when I found out Tom got the Bremerton area display on his Android from this newspaper’s Web site, at kitsapsun.com/traffic.
He was pretty quick in finding it, too. Jeremy Judd, the paper’s Web site director, said it went up only July 22, two days before Tom accessed it. The corporate office provides it in agreement with a private company called Total Traffic, which covers the nation.
I’m not sure how accurate it is, not having a smart phone that could test it while I’m on the road. It seems to always find red-level congestion near the Bremerton ferry terminal, and to show yellow at intersections with a traffic signal. It reliably shows the weekday afternoon backup on Highway 3 approaching Highway 304. It often shows slowdowns on Sedgwick Road and as I write this, it shows congestion on Locker Road at Sedgwick. I drove there to look but found nothing out of the ordinary.
I e-mailed Total Traffic asking how it gets its information, but I wasn’t hopeful of getting a reply, and I didn’t. That’s probably proprietary information they protect,
A state official told me he thinks Total Traffic has agreements with companies with large fleets, like delivery companies, and track the speed of the trucks. It’s a nationwide network and The Sun’s depiction starts with the Puget Sound area, with ways to zoom in and out.
The real-time data the state provides online for Snohomish, King and Pierce counties is derived from sensors in the pavement every half-mile or so, plus on freeway ramps, says Claudia Bingham-Baker of the Olympic region. The display is calculated by a computer based on the time it takes vehicles to travel between sensors.
The state does use pavement sensors, much farther apart, to collect traffic data here, but it’s for long-term planning and business inquiries about traffic volumes. It’s not shown in real-time displays. The assembled data can be seen on the state DOT Web site at www.wsdot.wa.gov/mapsdata.htm. Click on Travel Data. There are six such data collection stations in Kitsap County.