BROCKTON — If Gov. Deval Patrick can succeed where every governor before him has failed — in breaking the police union hold on expensive work details — he will deserve a laurel and hearty handshake from the people of Massachusetts who have been victimized by this pricey police perk.

There’s a reason 49 other states don’t require police to be used at every construction or repair site on public streets — they’re too expensive and they’re not necessary. In most states, civilian flagmen direct traffic and make sure the workers are protected from motor vehicles. The cost is generally in the $12 to $15 per hour range. But in Massachusetts, it takes a police officer in uniform to direct traffic — at up to $40 per hour (with a four-hour minimum). The companies, usually utilities, forced to hire these cops do what every other business does — they pass the costs onto consumers.

Now Gov. Patrick has taken aim at the work details, which some consider the third rail of politics. Two decades ago, Gov. William Weld made a similar proposal and the police unions sneered at him and told him to forget about it. Weld forgot about it — and no governor since has had the guts to take on the powerful unions.

But Patrick has strong allies this time, including House Speaker Salvatore DiMasi and Senate President Therese Murray. The three are motivated by a gaping hole in the state budget of $1.3 billion and a report outlining the need for $19 billion in transportation upgrades and repairs over the next two decades.

Replacing the cops with flagmen — only on “quiet” streets at first — would save $5 million per year. That’s not much, but it’s a start.

The minute the three state leaders made their joint announcement last week, the police unions began their well-rehearsed howling about how more police on the streets — even staring in the hole at a construction site — improves public safety. You get silly comments like this from Rick Brown, president of the State Police Association of Massachusetts: “I don't know how you put a flagman out there without endangering the public.”

But if taxpayers wanted — and could afford — more cops on the streets, they would be hiring more police instead of laying them off. Replacing $40 per hour traffic directors with $15 per hour men and women won’t compromise public safety one bit — and will go a long way toward restoring public confidence in state officials’ commitment not to waste their money.