All that plus a sea change in practices. I highly recommend reading the "Ask me about being a Traffic Engineer!" thread on the somethingawful.com forums (free preview for 10 days every month; all other times it's paywalled). That's a long-running Q&A thread with a former ConnDOT traffic engineer. Very informative and often hilarious...easy enough for newbies and transpo geeks to grasp.
Basically..."But We've Always Done It This Way" mentality is 10x as entrenched on the highway side of most state DOT's compared to the more progressive transit and complete streets sides. Old capacity-expansion habits from the 1960's die hard, the long view is hard to stick to when shortcuts/cost-cutting/deferrals are too easy, and community input is a worse day-to-day terrorscape than what gets reported. Most of the examples are from wonderfully inept ConnDOT, but it's pretty much universal. And, yes...PLENTY of first-world foreign countries are equally dysfunctional when it comes to highway policy so there are plenty of warts to go around even with the ones at the high end of the competence scale. Entrenched archaic policy and practices abound when it comes to all things asphalt.
