It's a multi-million dollar project to ease traffic wait times at the busiest border crossing in the country.
But some say the port of entry project is putting businesses in jeopardy.
The goal is to reduce border wait times to less than 30 minutes by widening the crossing to 10 lanes of traffic.
But meanwhile businesses say the project is doing more harm them good.
The culprit? A detour at the most southern tip of the Interstate 5 freeway. Port officials say they needed to close it to do electrical and utility work .
But because of this detour, San Ysidro boulevard is taking the brunt of the traffic since drivers have to head north along the main drag in order to catch the 5 north.
To make matters worse traffic is backed up near the port since drivers are confused over where to make a U-turn to take the detour.
The San Ysidro Chamber of Commerce says businesses are suffering, some closing all together.
Nancy Rasor owns the Postal Annex store on the boulevard. She says she has already lost 30 percent of her business.
"We're talking about businesses before the holidays who were thinking before the holidays they might go under and now they have this on top of it. You know they don't know whether they're going to make it. I've heard people tell me they're down 30, 40 even some have told me 50 percent," Said Roser.
This is the first phase of a three-part project, scheduled to be completed by 2015.
In the meantime, port officials are meeting with the San Ysidro Chamber of Commerce to try to ease the situation.