BROOKLYN - Mayor Michael Bloomberg has proposed a plan to expand the city's restaurant letter-grading system to include food carts, but the idea is not sitting well with everyone.

The New York City Department of Health says it isn't ready to take on a project of this magnitude yet. Officials say their inspectors are still getting used to the year-old restaurant scoring system.

Health officials also say that since food vendors don't have to operate at the same location every day, it may be difficult to track them down for a surprise inspection.

If the city does decide to begin evaluations for mobile food carts, it's not expected to go into effect right away because some restaurants are still waiting for their grades.