The K-12 education conference industry is huge and lucrative.

Just do a Google search on “education conferences” and you will get countless listings for annual events throughout the nation – and sometimes in other countries – that education professionals are strongly encouraged to attend.

MORE NEWS: Know These Before Moving From Cyprus To The UK

The headlines say things like “100 Best Education Conferences to Attend in 2018,” and “2018 Can’t Miss Education Conferences.”

Public schools respond to all the hype and send employees and officials to the events in droves. And the cost to taxpayers is massive, particularly in the form of travel costs.

As part of our latest series titled “School Spending Spree,” EAGnews.org sent public information requests to randomly selected districts throughout the nation, seeking information about tax dollars spent on travel in the 2016-17 fiscal year.

The response we received from many districts was breathtaking.

The Lubbock, Texas school district spent more than $1.4 million for hotels and air travel alone. The Palm Beach County, Florida district spent $1.1 million on hotels and air travel.

Some other districts on the pricey traveler list were Austin, Texas ($883,060 just for hotels); Vista, California ($322,540); Ector County, Texas ($337,154 for hotels alone); Parkway, Missouri ($243,524); Midland, Texas ($263,585); Bay County, Florida ($195,715 just for hotels); and Arlington, Texas ($187,989 just for airline costs).

A high percentage of school travel costs are obviously incurred by teachers and other school employees traveling to distant professional conferences. Their tabs for hotel rooms, airfare, and car rental are significant.

MORE NEWS: How to prepare for face-to-face classes

Public school officials vehemently defend professional development travel, saying it’s necessary to help educators increase their knowledge and skills.

That may be true, but some big questions come to mind, like how much knowledge is actually gained on those expensive trips, how much of it actually benefits students – and whether anybody bothers to find answers to those two questions, so they can measure the value of the travel investment.

We also wonder why travel is always necessary for professional development, when modern technology allows educators from all over the world to conference and converse without leaving home.

Beyond that, we wonder how much care is taken to ensure that hotel and airline costs are as inexpensive as possible, and whether schools with big money problems can justify massive travel expenses when they are cutting costs in crucial areas.

School officials routinely point out that many trips are paid for with federal and state grants.

Besides the obvious fact that grants involve our tax money, as well, we believe local taxpayers have a right to know exactly how much travel is funded with outside grant money, and how much is paid for with local school dollars.

Sometimes school officials struggle to figure that out themselves.

In 2016, 15 Pittsburgh school employees attended a conference in San Jose, Costa Rica, at a cost of $23,000, according to a report from KDKA-TV. Six staffers also ventured to a conference in Dublin, Ireland, at a cost of $11,600, the report said.

School board members approved the trips, after being told the feds would pick up the tab. They later learned differently.

“Lo and behold, after the Dublin trip was approved, we learned that the federal government grants do not cover reimbursement for international trips,” board member Terry Kennedy told KDKA.

Most observers probably assume that federal grants for school travel are exclusively for that purpose, so teachers and administrators might as well pack their bags and spend the money. But apparently, that’s not always the case.

In the Cobb County, Georgia district, $738,000 was spent on travel in calendar year 2016, and school officials defended the cost by saying that much of it was funded with grants. But they also admitted that the grant money “does not have to be spent on travel,” according to WSBTV.com.

Could that be the case in the numerous districts we found with huge budget deficits and huge travel tabs, like the Austin, Texas district ($30 million budget deficit, $883,060 spent on hotels in 2016-17) or the Philadelphia district (projected $905 million negative fund balance by 2022, but $152,631 spent on airline flights in 2016-17)?

Did those districts have the option of spending grant money on more pressing needs at home, but simply chose to use it for questionable travel instead?

We also have to wonder about redundancy and unnecessary cost when numerous school employees attend the same conferences.

On July 7, 2016, the North Kansas City school district spent $13,460.05 on 20 rooms at the Marriott San Antonio for the AVID Summer Institute. That averages out to roughly $670 per room.

The Lubbock, Texas school district spent a total of $13,146.72 in 10 transactions at the Churchill Hotel and DuPont Hotel in Washington, D.C. on July 20-21, 2016.

The Palm Beach County, Florida school district had a single transaction for $70,875 at the “Ritz Carlton Lake” – no date or location was listed.

Could two or three employees attend a conference – instead of 10 to 12 – and bring back pertinent and helpful information to share with colleagues, at much less cost?

School officials also need to explain why they pay for so many hotel rooms for events in nearby cities, when a little back-and-forth driving, even for a few days in a row, would be much more economical.

One example comes from the Alachua County school district in Gainesville, Florida.

It’s about a one hour, 45-minute drive between Gainesville and Orlando. But in fiscal year 2016-17, the Alachua district had 85 separate transactions at Orlando hotels – at places like Disney resorts, the Hyatt Regency, the Rosen Centre and the Florida Hotel and Convention Center – for a total of $35,662.96. That averages out to about $419 per transaction.

Some school districts with huge travel costs add even more expense by hiring professional travel agencies to make arrangements for them.

The Philadelphia school district’s travel documents listed 206 transactions with the Au Revoir travel agency, totaling $23,601.90. There were also 252 “agent fees” listed, mostly for $28 apiece, which came to $7,047.

That’s pretty inexcusable in the Internet age, when just about anyone can book their own hotels and flights in a matter of minutes.

It seems pretty obvious that public schools throughout America routinely send employees on a lot of expensive trips on a regular basis, with few outsiders noticing or questioning the practice.

The only way to cure that is for taxpayers and local media to wake up, ask questions, and hold the schools accountable for their use of our dollars.