Interestingly, I think until times get better, better road thechnology will not make it into the field unless it is only very slightly more expensive.
I propose several potential reasons for slow implementation of better technologies:
1. Engineers at state DOT's are probably older. That isn't a problem, but their roots are in what has worked for a long time, and new technology is risky.
2. When DOT engineers learn about new technology, if they can get someone to allow them to use it, it will be on a test basis and will have to be obvserved/monitored for years to ensure there are not problems. If development is recent, it will be a long time before states are confident enough in this technology to roll it out en masse.
3. Highway construction costs are awarded on a low bid basis (only to qualified contractors, of course). Unless specified in an RFP, it is likely only the least expensive materials that meet standards would be used. In addition, a contractor will be liable for problems for a contractually set time period for their work, and they may wish to stay clear of new technology.
4. Engineering costs may run high with new technology. It could be difficult to find a qualified engineering firm to design, inspection/testing and do construction engineering on a relatively new material. Those firms will be out there, but their costs will likely be high due to various factors inherent with specialized personnel. Federal legislation does not allow price to be a factor in awarding engineering contracts (brooks act requires qualifications based selection- actually a good thing), and so costs are generally not fully determined until after engineering work is awarded. This is pretty risky for DOT's without a lot of wiggle room in the budget.
Some of that above is obviously conjecture, and I would love an engineer to help out with input on that stuff. The above is just what I've put together.
