Hramblings: Improving Construction Zone design

The construction season is in full swing and while I'm inching along waiting to merge from 3 into 2 lanes, many ideas on how to improve the situation come to mind:

• Once the merge has occurred, don't allow additional merges within the reduced capacity area. Its perfectly ok to have vehicles exit the freeway in the construction zone, but permitting vehicles to join the traffic column takes the whole line of traffic down to a crawl.
• Keep construction traffic out of the reduced lane zone. Construction vehicles should travel in the construction area not with the traffic routing around it. Construction vehicles should enter the construction area at the start of the neckdown and leave when the lane is restored. If its a particularly long construction zone, that would be a good use for those shut down on-ramps. There is nothing more annoying than having a grader or backhoe trundling along causing further delays.
  
• Consider linking close construction zones. Adding a lane just to drop it again at the next bridge doesn't make sense.
  
• Consider signage that not only precludes passing in the lane to be dropped, but also requires a lower speed in it. This will prevent the necessity for the 5-10 mph rolling block setup by truckers.