Skip to main content

ODOT implements weather-activated speed signs

Oregon Department of Transportation (ODOT) has implemented digital variable speed limit signs over a thirty-mile stretch of Interstate 84 between Baker City and La Grande, replacing the standard speed signs in that area. The new signs will use traffic, road, weather and visibility sensors to lower the legal speed limit when ice, snow, fog or a wreck ahead requires drivers to slow down. Along with identifying the current legal speed limit, the digital displays can also show the reason for a reduced speed,
November 18, 2016 Read time: 2 mins
5837 Oregon Department of Transportation (ODOT) has implemented digital variable speed limit signs over a thirty-mile stretch of Interstate 84 between Baker City and La Grande, replacing the standard speed signs in that area.

The new signs will use traffic, road, weather and visibility sensors to lower the legal speed limit when ice, snow, fog or a wreck ahead requires drivers to slow down. Along with identifying the current legal speed limit, the digital displays can also show the reason for a reduced speed, such ‘ice’ or ‘low visibility’.

Roadside sensors feed temperature, visibility, road surface grip (traction), vehicle speeds and moisture levels data into the variable speed limit sign system measure. If a majority of cars and trucks are slowing down due to weather, poor road conditions, or a wreck ahead, the sensors can send a message to the signs to reduce the speed for all drivers. Likewise, when sensors detect poor traction, low visibility or other hazardous conditions, speed limits will be lowered and an appropriate warning message can be displayed. ODOT staff will also be able to manually adjust the speed limits, such as when a crash occurs or when construction activities require a slower speed.

“This section of freeway is positioned between the Eagle Cap and Elkhorn mountain ranges,” said ODOT Area Manager Ken Patterson. “This often creates microclimates with more severe weather patterns than adjacent sections of freeway.”

Ice, high winds with blowing snow, and limited visibility are some of the challenging conditions that catch motorists off-guard, resulting in a higher number of crashes than similar freeway sections.

“The idea behind these new signs is to warn motorists ahead of hazardous road conditions and get them to slow down before they enter a potentially dangerous situation,” Patterson said.

For more information on companies in this article

Related Content

  • New ice warning system aids safety on Swedish highways
    February 5, 2013
    A new road sensor system is set to offer more accurate warnings for slippery surfaces. The TrackIce system, developed by Mowic, is to be installed by road maintenance contractor Peab along a 30 kilometre stretch of highway E4 between Stora Essingen and Södertälje in Sweden. According to Mowic, the TrackIce system is quick to install without the need for cables, enabling it to be installed in remote areas where no power is available. The TrackIce central unit can also handle information from other sensors su
  • Innovia & The Ray feel the pulse
    March 15, 2022
    Getting drivers to slow down and space themselves safely on the road is a problem – but a collaboration between Innovia Technology and The Ray may have found a new way to do it
  • ITS World Congress debates perceptions of enforcement
    December 4, 2012
    The technical programme of this year’s ITS World Congress in Vienna includes a special session on the image of enforcement. ITS International examines the scale of the problem and what can be done about it. Debate on the merits and difficulties of enforcing speed limits appears centred on a conflict of principles. Put very simply, local communities, people living close to busy or hazardous roads, want to see traffic speeds calmed. Drivers on those roads, on the whole, want their principle of freedom to be m
  • High-speed WIM moves onto the main highway
    May 24, 2016
    High-speed weigh-in-motion is starting to make its mark on both sides of the Atlantic. As a transit country the Czech Republic experiences a large number of overloaded vehicles, which greatly increase highway maintenance costs. This prompted its Transport Ministry to trial an extension of the capabilities of the existing truck tolling system to allow the dynamic high-speed weighing of cargo vehicles. In effect the tolling enforcement gantries become weigh-in-motion (WIM) locations.