brain games Uncategorized

Traffic lights worldwide set to change after Swedish engineer saw red over getting a ticket

Great story of determination and science to overcome poorly time traffic lights and set a new standard around the world.

Have you ever been charged with running a red light when you knew you were innocent? It’s pretty crappy isn’t it. Well that’s all about to change.

A Swedish engineer’s umbrage at a traffic ticket given to his wife has led to a six-year legal fight and now a global change in the speed with which traffic light signals are timed.

After Mats Järlström lost an initial legal challenge in 2014, a federal judge in January this year ruled Oregon’s rules prohibiting people from representing themselves as engineers without a professional license from the state are unconstitutional.

And now Järlström’s calculations and advocacy have led the Institute of Transportation Engineers (ITE) to revisit its guidelines for the timing of traffic signals. As a result, yellow lights around the globe could burn for longer – ITE is an international advisory group with members in 90 countries.

Järlström, who studied electrical engineering in Sweden, challenged the ticket, arguing the timing interval for yellow lights fails to account for scenarios like a driver entering an intersection and slowing to make a turn. A slightly longer interval, he argued, would allow drivers making turns on a yellow light to exit intersections before the light turned red. Even a small timing increase would help – the automatically generated ticket in this case was issued 0.12 seconds after the light turned red.

Järlström said if the ITE accepts his solution, the duration of a yellow light in the right-turn scenario he described in 2015 would be extended from 3.2 seconds to 4.5 seconds using current input values – driver-vehicle perception-reaction time and maximum safe, comfortable deceleration. Such timing may vary depending on other considerations, but in general the adoption of Järlström’s formula should result in slightly longer yellow lights.

The ITE staff will develop and formalize the proposed changes to produce a final document called the Recommended Practice that will be submitted to the ITE Board of Directors for final approval in early 2020.


By Ted

I'm a former member of the Radio Television News Directors Association and during the last 30 years I've written news stories, sports stories, stories for children, puzzles, and plays for puppets.

Many of my ebooks are color picture books for children, and include printable black and white pictures at the end of a story. Please visit my blog for the latest information on my ebooks, and any updates or changes or comments. Ted.

PS: Please help stop cruelty to animals and support your favorite humane society or organization.