Public notice, which was missing in New Jersey, is also important, the experts said.
In Los Angeles, for instance, in preparation for the Olympics in 1984, the public was warned for months by traffic engineers and the officials that traffic would be terrible. Consequently, "a lot of people adapted and the traffic wasn't as bad as we thought it would be," said Richard Dowling, a transportation engineer at Kittelson & Associates in California.
It's hard for engineers to come up with examples of road changes that were done, as in the case of New Jersey's lane closing, as an experiment to test something out.
"It's very unusual to use the public as a guinea pig," said Dowling.
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