DOT and their proven, reliable contractor had experience with a certain method of rehabbing the joints between concrete slabs. A new technique was tried, and the first few attempts were not done well. The new technique showed promise, but there was a concern that if the new technique failed, there would be consequences to the state for trying a new technique rather than the tried-and-true method. To reduce the risk to themselves, the DOT went with the old method.
IME, DOT and transit agencies often shy away from new methods/techniques because they are raked over the coals whenever the new approach doesn't work out (see SF Bay Bridge, or the Big Dig [0]). That makes them risk averse to trying or sticking with innovative methods.
[0] I'm not saying that cost problems with those projects are completely due to new methods/processes, but significant chunks were.
DOT and their proven, reliable contractor had experience with a certain method of rehabbing the joints between concrete slabs. A new technique was tried, and the first few attempts were not done well. The new technique showed promise, but there was a concern that if the new technique failed, there would be consequences to the state for trying a new technique rather than the tried-and-true method. To reduce the risk to themselves, the DOT went with the old method.
IME, DOT and transit agencies often shy away from new methods/techniques because they are raked over the coals whenever the new approach doesn't work out (see SF Bay Bridge, or the Big Dig [0]). That makes them risk averse to trying or sticking with innovative methods.
[0] I'm not saying that cost problems with those projects are completely due to new methods/processes, but significant chunks were.