Rice is nice when trying to visualize highway traffic

It's as simple as rice flowing through a funnel. If you dump it in the funnel all at once, the funnel clogs and the pan that catches the rice fills up slowly. But pour it at a slower, more even pace and it flows more smoothly.

This simple idea by a Sammamish writer won the $1,000 Doug MacDonald challenge. MacDonald, secretary of the Washington Department of Transportation, put in $1,000 of his own money to ask the public to come up with a way to translate the transportation jargon "through-put maximization" into English.

The winner was Paul Haase, who beat 258 entries from as far away as England.

Haase wrote in his winning entry: "The physics of car-flow in a highway resemble those of rice poured through a funnel. If you pour slowly, you get little out, but if you pour too fast, the rice clogs and you get little — or nothing — out either. Car-flow involves similar thinking. For any highway there's a particular in-between speed that moves the most vehicles under typical conditions."

MacDonald came up with the contest idea earlier this year when he found himself with a little extra money and a lot of concern that the public wasn't really understanding the challenges of transportation officials.

Even though he was looking for ways to explain transportation jargon, not new transportation ideas, many of those who entered his contest offered fresh ideas.

There were some offbeat ideas, too, such as using helicopters to remove disabled vehicles from the road or using a license-plate numbering system to prevent some people from using the highways on certain days. One person wanted to charge entry fees at the border for non-Washingtonians to enter the state.

While "through-put maximization" — moving the maximum number of vehicles through a stretch of highway at the maximum speed — might sound good to transportation technophiles, much of the public doesn't understand it, said MacDonald.

Hence, the contest.

"The winner was so clear," he said. "Once I read it and thought about it all night, I realized it was perfect."

Haase, 43, a freelance science writer, said he drew his idea from two sources: a professor at the California Institute of Technology who talked about the flow of material by shaking a cornflakes box, and what he knows about cooking. "Rice is slippery and vaguely car-shaped," he said.

Haase said he didn't try the experiment himself because he didn't have a funnel, but said it simply made sense.

Having more buses means you're putting less rice in the funnel; banning trucks from roads at certain times of the day means you're taking out big chunks of rice. "If you take some rice away and don't pour for a while, the clog will clear," said Haase, who hopes to turn his traffic ideas into a book.

MacDonald has been busy demonstrating it in his Olympia office. Each grain of rice is a car; the funnel is a road. "If the funnel jams up, nobody moves," he said. "If you pace the flow of traffic you can get much more rice through the funnel."

Ways to do that include ramp-metering and hot lanes, where motorists pay to drive.

"This is why rice is so powerful. It's the perfect example," MacDonald said. "If there's more drivers that cause backups, all the rice is stuck in the funnel."

The prize will be awarded at a National Academy of Science meeting next month. Haase said he has no firm plans for the money, but has his eye on a piece of art.

According to the DOT, 80 percent of the entrants in the contest were men. Ideas ranged from eliminating HOV lanes to forbidding SUVs from using the carpool lanes.

One of the finalists, Daniel Dornan, an engineer from Florida, compared traffic congestion to mowing lawns in his childhood. When the grass was long and wet it jammed the mower and clogged the grass catcher, which is similar to what happens on highways.

"To solve my mowing problem, I raised the cutting blade, reduced the length of grass entering the grass-catcher, and increased the mower's efficiency. If applied to traffic congestion, similar results are possible," he said.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com