I attended a presentation by Howard Preston of CH2M Hill yesterday about the newly released Traffic Sign Maintenance Management Handbook (warning: large file). There is a full day course coming up on the topic on November 4th in Arden Hills, MN that would be worth your while if you're involved with sign maintenance.
Sign maintenance has become a huge issue since the Federal Highway Administration passed requirements that all signs need to be in accordance with the Manual on Uniform Traffic Control Devices by 2018. Sounds logical but there are new standards for how reflective signs have to be. In reality it means a big replacement effort needs to be undertaken.
To put this in perspective, most suburban cities have +/- 10,000 signs. In round numbers it costs about $150 to replace a sign. So to replace a typical city's inventory easily costs more than a million dollars. Tough to reconcile that with the nominal budget most city's have for sign replacement (less than $100,000). A big complicator is that many agencies don't have a good inventory database.
So agencies are scrambling to develop inventories of what they have while also developing a reasonable policy for how they're going to provide adequate maintenance to ensure their signs meet minimum standards. Key to any sane policy is reducing the number of signs so the inventory matches the available maintenance budget. This means getting rid of all of the "slow children at play", "deer crossing", "falling rock" signs since they are proven to have zero benefit (other than the temporary political benefit of giving a resident what they want). All of the unneeded stop signs should go as well as 30 mph speed limit signs on residential streets (the default speed limit on a residential street in Minnesota is 30 mph – no sign needed).
There aren't any sign police out there, so agencies could try to cheat the system. The downside of this strategy is that they'll be opening up their checkbook if there's a crash and they didn't have a reasonable policy they followed consistently. The agency would have significant liability.
This doesn't mean engineers always have to play by the book. At least in Minnesota, there is significant case law that backs up a licensed engineers right to exercise "engineering judgement." Key to exercising engineeirng judgement is documenting the situation and the rationale for deviating from standards. Even if something bad happens, the Minnesota courts have upheld engineers' immunity as long as they were thoughtful and documented the situation.