Lutfi,
your best bet is to call a fabricator. In NYC, bridge steel - material, fabrication, delivery, erection, and painting - runs about $2 to $2.50 per pound; $4 to$5 K per ton.
There are several factors to consider, such as - location of the fabricator, shipping, site constraints for erection, complexity of the project, working hours,client requirements (DOT's tend to be more stringent than private owners), union vs. non-union, Buy-America provisions.
You could also look in Means and make the necessary adjustments for location; that should put you in the ball park.