I mainly used AAroads for signage information over the years. What sites have you all found useful for road and highway information? Here are some of my favorites:
http://www.us-highways.com/- This is a good site for US Route logs and description on signage history. Not many pictures but not short on fact and figures. This site actually has a ton of information on the old and modern Florida Road system.
http://www.usends.com/- This site is shows almost all the historic and current end points for US Routes. It has literally every US Route that existed on greatly defined map. This is probably the best site for finding historic road alignments and end points. Lots of signage photos are here as well.
http://www.interstate-guide.com/- This a great site for information on the Interstate System. This is very similar to USends except with a larger emphasis on photos instead of maps.
http://www.steve-riner.com/nmhighways/NMHome.htm- Not exactly the best looking site but this guy did a ton of research into the New Mexico Highway system. This is one of the harder states to get accurate highway information on and this guy has basically everything you could want that is New Mexico.
http://www.historic66.com/- This is a great site on Route 66. I used this site as a reference for a lot of the Old 66 road alignments which detailed extensively, or at least more so than I can find on most sites. This sites has a lot of reference maps.
http://www.theroadwanderer.net/route66.htm- Another good Route 66 site that has a lot of information, photos and maps. Also very good for old 66 alignments.
http://www.arizonaroads.com/index.html- This site hasn't been updated in a long time but contains a ton of information and photos on Arizona Roads. Since the system hasn't changed much in rural areas most of the information still accurate. There is some highly detailed maps of Arizona and New Mexico along with a nice goof signage stub.
http://www.kurumi.com/roads/ct/- This is a very good site for anything highway related to the state of Connecticut.
http://www.cahighways.org/- An excellent site for anything related to California Highways. This site is mostly informational, so if you are more into pictures rather than reading it isn't for you.
http://www.michiganhighways.org/- A very well put together and good looking site for Michigan highways. Contains a ton of information that is very organized.
http://www.dangerousroads.org/- I saw someone suggest this here on the forum. Very cursory information but it gives you ideas what to look for a quick road trip adventure on the twisties and turnies.
http://www.route6tour.com/aboutus.htm- Solid site on US Route 6.
http://usroute89.com/- A solid site on the often overlooked US 89.