CHICAGO (CBS) — New concerns have erupted over Mayor Rahm Emanuel’s planned congestion premium – the extra $2 tax at downtown parking lots and garages suggested as part of his budget plan.

As CBS 2’s Susanna Song reports, some aldermen say the tax unfairly targets more than just rush-hour drivers downtown.

LISTEN: WBBM Newsradio’s David Roe reports

As it is, a parking garage at Clark and Lake streets charges $21 per day, and that is for the early morning special. Mayor Emanuel says the $2 fee on top of that steep price is to get people who drive downtown during rush hour to pay more.

But the plan doesn’t specify time of day. That means even when traffic is light in the night and early morning, drivers would still be subject to pay more.

Another confusing factor in this proposal that has aldermen upset is that the plan does not set geographic boundaries for the tax.

When the plan was brought up, the mayor said it would apply to lots around downtown that charge the most, but any places that charge more than $12 would be see the extra $2 imposed.

Thus, even if you don’t work downtown, but you come into the city to watch a game at the United Center, Wrigley Field, or U.S. Cellular Field, you can expect to pay more.

One Chicagoan, Gerald Latham, said the fee would just be too expensive.

“All those places too? See, I didn’t even know that. Wow, that’s too much. It’s too much. If you’re a hard-working person, they shouldn’t be jacking stuff up, especially the way the economy is these days. You know, every little bit of money counts. Everybody is fighting already for any type of penny or dollar or whatnot, but to do that to somebody that’s a hard-working person? That’s ridiculous.”

Theresa Kunach of the White Palace Grill called the congestion tax “unfair” and “ridiculous.”

Budget Vice-Chairman Ald. Brendan Reilly (42nd) said earlier this week that he would rather the congestion tax would be applied only during the day, but his colleagues may not feel so strongly.

“It is a substantial source of revenue for the city – close to $28 million annually – so I think many of my colleagues are resigned to the fact there will be a parking tax,” Reilly said this week.

But now, aldermen who are against the plan are saying they will try to amend it so if focuses more on the rush hour when there is a lot of congestion.

Emanuel’s budget has already passed out of the Budget and Finance committees, and is set for a full City Council vote on Nov. 16.