It's the only North-South corridor through Hancock County. Thousands of people travel Highway 603 everyday. All that traffic lured Gary Catalano to open a used car dealership here.
"It's a good road. It's a four lane highway for people coming from different parts of Mississippi, Louisiana, Alabama. It's the main thoroughfare going into Bay St. Louis and Waveland," Catalano said.
Catalano and others expected more growth along the corridor by now, but until recently, the county hasn't had the money to bring water and sewer service to the area.
"Naturally a lot of people, a lot of developers, are waiting to see when the water is going to be put on the west side. I'd like to see it happen yesterday myself," Catalano said.
"It's been relatively slow because of water and sewer and zoning," Realtor Paul Seckso said.
Over the last three years, water and sewer lines have slowly been laid, and there is a county wide zoning plan in place. Realtor Paul Seckso says his job of attracting business to Highway 603 should get easier.
"You see what's happening on Highway 90, you've got a number of new businesses on Highway 90. That's the same thing that's going to happen on 603," Seckso said.
"It's just starting to happen. I personally think it's now starting, but slowly," Highway 603 Business Owner James Quakenbush said.
He points to a new office and retail complex going up less than a mile south of his business, as well as a planned housing development further down the road.
"I feel in the next few years we should really see things turn around," Quakenbush said.
Business owners we spoke with say attempts by Bay St. Louis and Waveland to annex the highway will have no impact on development. They say Highway 603 will continue to grow anyway.