Approximately two years ago, I suggested installing variable speed limits on the Split as a way to smooth traffic flow and improve safety during periods of congestion. It looks like Seattle is now doing exactly that on I-5. I still think it would be a great option for the I-70/I-71 split, and really any highway that experiences regular congestion. Given the $1.7 Billion price tag, and the dire budget situation at every level of government, why wouldn’t we experiment with cheaper alternatives that can be implemented more quickly first?
Revolutionary new traffic system to “cut injury accidents 30 percent”
By ALEX SILVERMAN
KIRO Radio…The system will vary the speed limit between 40 and 60 miles per hour depending on traffic conditions, close lanes when there is trouble ahead, and let drivers know when to merge to avoid bottlenecks before they even have time to develop.
The technology’s been used in Europe for several years, but Seattle’s system, along with one in Minnesota, are the first in the United States. “We’ve learned from them, studied their data,” Rubstello said.
The results across the Atlantic are significant. Injury accidents have been reduced by 30 percent, while minor fender-benders have been cut by 15 percent. Rubstello says she expects the same results here in Seattle.
…According to Lomax, Seattle’s active traffic management system could start a revolution. “If this is successful, every major city is going to go to school on this.”
Love this idea John! And it’s certainly worth a try considering the price tag associated with the major structural overhaul being proposed.
really cool idea…like it a lot!
Why wouldn’t we? Well, whoever will economically benefit from the split reconstruction would not like this much cheaper, smarter alternative. Really though, I’d have to say why not go even cheaper and implement a flat lower speed limit across the board first (maybe 40 MPH?) and then see if we need to go with the electronic sign route. The split is only one mile for each downtown leg and if you’re using both it’s only two, so it’s no big deal. During peak hours you’ll likely be going slow anyway. Enforce it, particularly during peak hours, and erect large warning signs for those speeding. It is an urban highway in a dense urban area after all.
Another thing I should have included before is that the number of crashes per year was 1200 from 1999-2001
http://www.dot.state.oh.us/projects/7071/Study/PublishingImages/MapsandCharts/Crash_Data.pdf
and went down to 800 per year from 20??-20??.
http://pubserv.ci.columbus.oh.us/transportation/Document_Library/PROJECTS/I-70_and_I-71_Corridor.pdf
That’s a reduction of 33.33% in crashes on the split and that was without doing a thing. Of course, that number would probably be even lower, but this is most likely from the same data that includes extra heavy traffic from a closed I-670 stretch being dumped onto the split.
Found an ODOT quote in a 2009 article on your website which correlates with the 33.33% or 1/3 drop in crashes, but who knows if the figure is actually from 2009, knowing ODOT penchant for selectively choosing certain years and certain conditions when the data was taken. Still, it’s a significant drop even if taken at face value.
“The split is one of the most congested areas in the state, ranked fourth statewide in terms of crashes and congestion, averaging two a day,” ODOT spokeswoman Nancy Burton said.
http://xingcolumbus.wordpress.com/2009/01/23/16-billion-for-downtown-split/
The 1999-2001 crash data above quotes three crashes a day as the average.