So John Liu has managed to take an excellent idea — tolling the East River bridges — and turn it into a policy disaster.

The key component of Liu’s plan, which he says would raise $410 million annually, isn’t the tolls — it’s the exemption for city residents. Here’s what Liu said at an Association for Better New York event today:

To get that money, we would toll the East River Bridges for non-city residents. It’s something that’s been talked about before, and I think certainly makes sense, and is more realistic than a restoration of the commuter tax — that I would love to see, but I’m not sure how open Albany would be.

Of course, Albany is just going to fall in love with a toll plan where Nassau, Suffolk, and Westchester pay, while New York City doesn’t.

Here’s an excerpt from the press release that accompanied the release of the “People’s Budget” — an overall fiscal plan that Liu released in his capacity as comptroller:

Tolling the East River Bridges would mean that membership — or in this case, residency, New York City residency — has its privileges. Non-residents commuting by car can and should contribute to the upkeep of our city’s infrastructure.

By exempting motorists who live in the five boroughs, Liu’s plan would not solve the city’s transit funding problems — the next MTA capital program will still have a gaping hole. (Compare Liu’s $410 million to the $2.8 $1.5 billion projected net revenue from the Sam Schwartz plan.) While Liu suggested devoting revenue to “infrastructure,” he also mentioned that it could be used for “offsetting increased city contributions to the MTA,” which might just lead to tolls that pad other areas of the city budget.

It’s somewhat baffling why Liu would propose a non-starter like this. Exempting millions of motorists negates the value of tolls as a tool to meaningfully reduce congestion, and it undermines the notion that motorists should pay for using roads. Let’s hope this idea doesn’t infect the other campaigns.