MADISON, Wis. -

The morning commute for drivers could be longer than normal Wednesday due to the fresh layer of snow that is falling in Madison.

WISC-TV meteorologist Haddie McLean said 4 inches of snow has fallen on the southwest side of town, as of 6:50 a.m. She expects the snow to wrap up in the Madison area around 9 a.m. Heavier snow has fallen south and west of Madison overnight.

Madison Streets Superintendent Chris Kelley said because of the snow over the past few days, all city streets will be plowed, starting at 9 a.m. Wednesday.

The city requires 3 inches of snow to fall before conducting a full plowing operation. Kelley isn't sure whether 3 inches has actually fallen at the official monitoring station at the Dane County Regional Airport on the city's northeast side. However, Kelley said the amount of snow over the past few days combined made him decide to call for a full plowing operation.

Thirty-two crews have been out overnight applying salt and salt bring to main roads, connector streets, bus routes and streets around schools and hospitals. Another 32 crews will be called in to work on the main roads as of 7 a.m.

In addition, another 100 crews, including private contractors, will be called in as of 9 a.m. to conduct the residential plowing operation. However, Kelley said he does not expect to declare a snow emergency for Madison, since warmer temperatures soon should help melt a lot of the recent snowfall.

Kelley said despite the efforts of streets crews, there are still slippery spots on area roads. He advises commuters give themselves extra time to get to work Wednesday.