I work a full time job as a roadway/bridge inspector.My goal this year as a newbie is to flip at least 1 property this year in my backyard and get the game rolling

The state mows the grass along this roadway, but skips around the sign with the mowing tractors.

Do I have to wait for the street to be built in order for me to start with the contraction of my home, or can I just drive on the "dirt way"/"planned roadway" to my property?

There has been a lot of investment in infrastructure the past several years- new major roadways being built and areas of the city being revitalized. 

While I was in southern Oregon I noticed several homes with missing roof shingles due to the high winds, coupled by a few boat covers in the roadway with no boats in sight. 

I work on roadway, bridge, and municipal projects (water & wastewater)

And you have no advance planning on infrastructure and road ways etc.. if every lot got built today in lehigh you would have grid lock.. those lots have been traded at tax sales now for 60 years.