ON THEIR first test drive last week, the new Senate rules worked just like the tougher seat belt law they advanced: Their mere presence caused everyone to use restraint.

It was no accident.

The beauty of the new rules — just like the seat belt law — is that they positively affect behavior even when they aren’t invoked. That’s something critics of both the rules and the seat belt law — who, ironically, tend to be different people — have either failed to grasp or refused to acknowledge.

We all know about the effect of a tougher seat belt law, well-documented in studies: Simply empowering police to enforce the law causes more people to buckle up. That’s because most people obey the law simply because it’s the law, or else because they have some reasonable fear that they might get caught and punished if they don’t. (One reason our seat belt law isn’t particularly effective is that some politicians have convinced people that it isn’t the law, but that’s a different issue.) Only a tiny minority actually have to be arrested for the law to work.

There’s nothing strange about that. The primary goal of nearly all of our laws is to deter bad behavior; when we have to punish offenders, the law has not been as effective as it should have been.

The Senate’s new anti-obstructionist rules are at their best when they work the same way. And that’s what happened with the first controversial bill the Senate took up this year, the measure to remove the handcuffs that had prevented police from enforcing the state’s seat belt law.

No opponent was denied the opportunity to have his or her say on the bill; senators got to offer all the amendments they wanted. And once the Senate had debated and voted on all those amendments — a process that took about four or five hours over the course of four days — the opponents summed up their arguments and sat down, and the Senate passed the bill.

“I think they realized that with the amount of support that the seat belt bill had that they were running a risk of a cloture vote,” said Sen. Larry Martin, a chief architect of the new rules, said of seat belt opponents. “I do think that the fact that the threat was there ... I don’t believe people are going to be as quick to push the envelope as they’ve been in the past, to get up and grab the podium and say ‘You’re gonna have to sit me down,’ because we might oblige them.”

On its surface, it would appear that the seat belt bill would have passed this year even under the old rules: 33 senators voted for it, and the old rules required 28 votes to end a filibuster. But that overlooks two realities: Some senators will never vote to end a filibuster, no matter how strongly they support the bill being blocked; and it is a common practice for some senators to do everything they can to sabotage a bill, but then vote for it in the end, so they can claim to have been on the popular side of the issue.

The new rules do nothing to prevent either practice, but they make both less effective, by reducing the number of senators it takes to stop a filibuster. It now takes 26 votes if all the senators participate, and fewer as senators go home. That second provision is especially important, because fair-weather supporters tend to be ones who skip out on the debate. Their absence used to actually aid the filibuster; now it doesn’t.

While the atomic bomb of the new rules debate didn’t have to be launched, Mr. Martin points to two less-notorious new rules that were used as helping the seat belt bill along.

When a seat belt opponent proposed requiring police to keep statistics on the race of drivers in all traffic stops, he was blocked by the new rule that makes it more difficult to attach unrelated amendments to bills. Opponents had to fall back on an amendment that required police only to keep racial statistics on seat belt violators; that had the Senate hung up for a while before it was rejected, but not as long as the broader amendment, which invited a practically unlimited debate on all of the state’s traffic laws, would have taken.

The other rule that was important in the seat belt debate makes it difficult to amend a bill on the final of three required readings. Mr. Martin points to this rule as speeding things along by “pretty much finishing the debate on second reading,” but I believe it had an even more significant effect.

I was skeptical of this provision, because another rule makes it easy to cut off a filibuster on second reading. Taken together, that means that if a bare majority could invoke cloture early on, it could prevent any debate that is aimed at producing compromise.

But during the seat belt debate, the rule worked just the opposite way. The majority knew they might need the support of some skeptics to pass the bill. So when opponents raised even potentially legitimate concerns, supporters offered amendments to address them. I’m not crazy about all the amendments, but the honorable goal of extended debate is to accommodate the legitimate concerns of opponents. And that was done in this instance.

It’s still far too early to declare the new Senate rules a success or a failure. But when they were proposed, Democrats made it sound like they actually required the majority to artificially curtail debate — just as detractors act as though the new seat belt law would require police to pull over every lawbreaker. That’s not going to happen on the highways, and, at least on this crucial first test, it didn’t happen in the Senate.

Ms. Scoppe can be reached at cscoppe@thestate.com or at (803) 771-8571.