The US Department of Transportation (USDOT) has announced funding of $500m for 47 projects under the fourth round of its Transportation Investment Generating Economic Recovery (TIGER) 2012 programme.

Under the grant, 47 transportation projects will be carried out in 34 states and the District of Columbia.

"Ray LaHood, US Transportation secretary, said: "TIGER projects mean good transportation jobs today and a stronger economic future for the nation.""

TIGER grants are used to finance those transportation projects that are difficult to be funded through other federal programmes and are awarded on a competitive basis.

Ray LaHood, US Transportation secretary, said: "TIGER projects mean good transportation jobs today and a stronger economic future for the nation."

USDOT will use more than $120m for critical projects in rural areas from the TIGER funding of $500m, and will allocate about 35% of the fund for road and bridge projects.

The 35% funding will include $30m for replacing, upgrading and improving rural roads and bridges for the safety of users.

A part of the grant will also be used to support passenger rail projects, freight rail projects, transit projects and construction of port projects.

TIGER grant also has a percentile allocated for the multimodal, bicycle and pedestrian projects and three grants to create jobs and address critical transportation needs in Indian country.

The department is expecting to see 27 projects start in the next six months from the first three rounds of funds from TIGER.

The four rounds of TIGER programme have cumulatively provided a total of $3.1bn to 218 projects in all 50 states, the District of Columbia and Puerto Rico.

The fiscal year 2013 appropriations bill, which is under consideration, may provide $500m for the next round of TIGER grants.