Nearly a month ago, the three national pupil transportation associations wrote to the Labors' International Union of North America (LIUNA), requesting that the union not negatively represent the yellow bus in its highway bill reauthorization campaign.

But on Monday, the union launched its "Getting Schooled in Infrastructure" tour with a conspicuous centerpiece: a school bus that appears to have been smashed by a fallen piece of bridge.

The bus (pulled by a tow truck) will travel through more than 22 cities and congressional districts. LIUNA officials said that the goal is to press Congress to pass a long-term, full-investment highway bill this year.

“It’s time to stop sugar-coating this issue,” LIUNA General President Terry O’Sullivan said. “We are not trying to scare people, but we are trying to wake people and Congress up.”

Mike Martin, executive director of the National Association for Pupil Transportation (NAPT), had a different take on the big, yellow prop. On Tuesday, he sent NAPT members a message denouncing the union's tactic, which he said uses the school bus "in a denigrating fashion."

"The apparent intent of LIUNA’s campaign is to create an impression to the media and public that children riding in school buses are unsafe without the highway bill funding LIUNA is seeking," Martin said. "This message is incorrect, misinforms students and parents alike, and most importantly, is irresponsible."

Martin told SBF in an interview that LIUNA didn't respond to or acknowledge the letter that the school bus industry groups sent on May 22. It was signed by the presidents of NAPT, the National School Transportation Association and the National Association of State Directors of Pupil Transportation Services.

When they wrote the letter, the pupil transportation associations had been informed that the union was planning to use the yellow bus in a non-flattering way, although Martin said that they didn't know all of the details.

The smashed school bus prop that was launched on Monday — and which is slated to be on the road for six weeks, making stops in at least 10 states and Washington, D.C. — is "bad for the school bus brand," Martin said in the interview with SBF.

"There is no increased risk to children" because of the state of the nation's infrastructure, Martin added. "Our safety statistics are exemplary. ... We work hard to be the safest form of ground transportation in the United States."