Missouri Gov. Jay Nixon did something a little weird last Thursday: He vetoed $33,000 from the Department of Transportation’s budget to punish MoDOT for commissioning a poll on Missourians’ attitudes about the Legislature’s decision to lift the state law requiring motorcyclists to wear helmets.

We’ve had our differences with MoDOT’s director, Pete Rahn, but we think an agency whose job includes keeping the highways safe was perfectly within its rights to find out what the state’s citizens think about an important issue of highway safety.

Last month Mr. Rahn said a telephone survey of 2,050 residents showed 84 percent of them support the current law requiring motorcyclists of all ages to wear helmets. He said that National Highway Traffic Safety Administration estimates that in 2007, the helmet law saved 42 lives in Missouri.

“By a 9-to-1 ratio, Missourians know this simple fact: Motorcycle helmets save lives,” Mr. Rahn said. He added, “This makes as much sense as going out and ripping out median guard cables on our interstates. It will have the same effect: More people will die on our roads.”

Some state lawmakers and “helmet freedom” advocates said the poll — and Mr. Rahn’s advocacy — was an improper attempt to influence Mr. Nixon’s decision about whether to veto the helmet law the Legislature enacted in April. Lawmakers decided that motorcycle riders 21 and older could ditch their helmets unless they are traveling on interstate highways.

Mr. Nixon agreed, whacking $33,000 from MoDOT’s budget (the amount the poll cost), saying it was an inappropriate use of tax dollars to influence a public official, i.e., him.

On Friday, a spokesman for the governor said that decision doesn’t mean that Mr. Nixon has decided to sign the helmet-law repeal. The governor has until July 14 to sign or veto the measure or take no action, thereby allowing it to become law on Aug. 28.

The Missouri Highway Patrol says that some motorcycle riders, unaware of the fine points of legislative procedure, already have removed their helmets. The patrol’s public affairs office told the Associated Press last week that troopers are reporting a large number of motorcyclists riding bare-headed.

If the riders are confused now, just wait until their heads bounce off the pavement a couple of times.

Newspapers around the state — including this editorial page — have opposed lifting the helmet law and have urged Mr. Nixon to veto it. The public knows that in addition to adding to the death toll, the costs of caring for traumatic brain injury are huge. In most cases, those costs will passed onto the general public.

If society bears the cost, society makes the decision. And that decision, as we’ve said before, is a no brainer — veto it. And give back MoDOT’s 33 grand.