Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The “twilight zone” of traffic costs lives at stoplight intersections

15.03.2012
Hundreds of lives are being lost each year in the United States because of mistakes made in what engineers call the “dilemma zone” – that area before a stoplight intersection where the traffic light turns yellow and the driver isn’t sure whether to stop or go ahead.
New research at Oregon State University will help to more precisely identify that danger zone. Traffic engineers can then use than information, along with advanced technology that can monitor the speed and location of oncoming traffic, to improve yellow-light timing and help address this problem.

When more widely implemented, this approach should help reduce driver confusion, add certainty to how intersections should be managed, and save lives.

“There are more than 30,000 traffic fatalities each year in the U.S., and about 2,000 of them occur in stoplight intersections,” said David Hurwitz, an OSU assistant professor of transportation engineering. “We think those crashes can be reduced with a better understanding of exactly where the dilemma zone is and how traffic lights and other technology can be adjusted to help manage it.”

Factors that lead to the problems in the dilemma zone include driving speed, distance to the stop light, driver skills, laws that vary by state, occasional scofflaws who are trying to “beat the red light,” and simple confusion by drivers who want to do the right thing but aren’t sure what it is.

There are many variables involved, Hurwitz said, such as vehicle speed and position. To help address that, researchers in one recent study used a tool called “fuzzy logic.” This provides a way to produce more exact decisions with inexact data, which in this case can include everything from drivers with very different skill sets and reaction times to automobile speeds and road variability.

Based on their speed and proximity to an intersection, when the traffic light turns yellow a driver has to make a decision whether to stop or proceed. A driver who is some distance away usually stops; and a driver who is extremely close to the intersection usually will go ahead. Those decisions are fairly easy. But the “dilemma zone” is the area where the choice isn’t so obvious, and the wrong decision can have serious, sometimes fatal consequences.

Complicating that, Hurwitz said, is that laws vary widely by state. In Oregon, for instance, the law requires that a car stop on a yellow light if it is safe to do so. In some other states, it’s legal to proceed on a yellow light, and even be in the intersection during a red light, if the front axle of the vehicle crosses the stop line before the light turns red.

Different laws can contribute to different driver behaviors, and national standards do not now exist.

Stop too suddenly, and you’re apt to have a rear-end collision with the vehicle behind you. Proceed or turn left when you shouldn’t, and even more serious crashes can occur, including head-on and side impacts. And based on the speed limit, the length of a yellow light at an intersection can vary greatly.

“In traffic engineering, consistency and uniformity is a critical concern,” Hurwitz said. “We want conscientious drivers to know what is the right thing to do. Given so many variables and differences in state law, that can be difficult.”

The findings have been published in two recent studies, in research that was supported by the Vermont Agency of Transportation and the Lilo and Richard Smith Transportation Fellowship.

“We want to help drivers know whether to stop or proceed, and do it in a manner that is safe,” Hurwitz said. “This approach should help accomplish that, prevent accidents and save lives.”

About the OSU College of Engineering: The OSU College of Engineering is among the nation’s largest and most productive engineering programs. In the past six years, the College has more than doubled its research expenditures to $27.5 million by emphasizing highly collaborative research that solves global problems, spins out new companies, and produces opportunity for students through hands-on learning.

The study this story is based on is available online: http://bit.ly/A2THta

David Hurwitz | EurekAlert!
Further information:
http://www.oregonstate.edu

More articles from Transportation and Logistics:

nachricht Study sets new distance record for medical drone transport
13.09.2017 | Johns Hopkins Medicine

nachricht Researchers 'count cars' -- literally -- to find a better way to control heavy traffic
10.08.2017 | Florida Atlantic University

All articles from Transportation and Logistics >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>