That is a great idea, but by crowdsourcing I assume you mean the end-users reporting the accident, the work zone, etc. correct?
I love that idea and it is a old/tested one, but from a safety perspective do we want people touching their phones while driving to report the location? If they wait till they reach their destination to report, the accident may be cleaned up or the exact location data of the work zone may become inaccurate. Also, who would be in charge of removing that data, checking if an accident is gone, etc?
Just some random questions I am throwing out there. I was going more for a very cheap 3G/4G-enabled device to broadcast live to a "City API". Thoughts?