The railroad crossing at Urban Avenue in Westbury reopened Thursday following the construction of an underpass.
The project was the first of eight crossings the Transit Authority and LIRR are improving as a part of its third track project.
The Urban Avenue crossing was completed in six months.
The MTA says it offered cash incentives to the contractor and used new technology to build the bridge quickly.
Officials say lower-grade crossings are safer for traffic.
The MTA police says in the last five years there have been 120 incidents at the crossing. In February, three people were killed when their car was hit by a train at the School Street crossing, just a mile from the crossing on Urban Avenue.
Town of North Hempstead councilwoman Viviana Russell lives on Urban Avenue and says the construction created some parking problems, but she's pleased the roadway opened so quickly.
The MTA says the next grade crossing to be completed will be at Covert Avenue in New Hyde Park.
The crossing is expected to open in mid-October.