How to report speed changes on a highway

I'm trying to report a changed speed limit but finding the mapshare reporting tool confusing. First of all, should I choose sign board or just speed limit? If I choose speed limit, where do I place the pin? I have tried placing it somewhere in the middle, with the intention of adding the start and end flags, but as soon as I place the pin, I can't move the map to place the start and end flags. Or am I supposed to create two separate reports, one for each end of the speed restriction but indicating traffic flow in opposite directions?