Interested in what you can’t see? That’s what you’ll learn about at these free downtown historic walking tours, with the first one slated for July 31, 2014. Given by members of the Historic Preservation Commission of the City of Columbia, the tours will focus on what you can — and can’t see.

All four of the upcoming tours start at 7:30 p.m. at the “Key” at City Hall at Broadway and Eighth Street. The first tour will cover Columbia’s brick streets, but not the part you can see. The other walks include an August 14 walk to view Columbia’s historic hotels and theatres, the Sept. 18 event will cover downtown worship centers and Oct. 30, the last walk, will take a look at places where ghosts and other scary tales lurk.

For the walk on Thursday, Patrick Earney, HPC member and project engineer at Trabue, Hansen & Hinshaw, Inc., will discuss the engineering under and around the brick streets of Columbia, Missouri.

What? Who cares? You should. Many of these streets are more than 100 years old and while they’ve lasted, those dips and ridges that make your car go bump in the day and the night when you drive on them are due in some cases to the poor foundation under the bricks.

As Earney noted in an email, “The take away for the average person is that a street laid 110 years ago is still viable and would still be performing well had they been maintained.”

There’s another value said Earney, one that not every one would recognize at first glance or first drive.

“Each brick was touched by at least two people — he who made it and he who installed it. They’re not all the same, and the rows aren’t exactly straight. There’s a human element to a brick street that another street pavement doesn’t possess,” Earney wrote in a recent email.

In this day and age of disposable, manufactured items, a hand-made, crafted item can hold value for those who see it.

Wonder where those brick streets are? Here’s a map that shows where they are exposed and hidden.

Are those bricks or bucks under your feet?

Just as important, these brick streets may end up costing — or saving — you money some day. Proponents of brick streets cite the fact that they last. Remember the part above that mentioned some of them are more than 100 years old? Advocates for spiffing up and even uncovering some of the brick streets say the reason they were covered during the 1960s and 1970s is because they weren’t maintained. They also point out that asphalt streets must be repaved every 15 or so years, making the apparent savings of covering brick streets instead of repairing them a false frugality over time.

On the other hand, some people point to the cost of repairing the brick streets, pointing out that when the brick street were laid, labor costs were a fraction of today’s costs. Repaving using bricks calls for craftsmen and craftswomen, not just rollers.

Like it or lump it, on March 17, 2014, the City Council passed a Brick Streets Policy Resolution PR 229-13 that says the city will not remove covered or exposed brick pavement within a “Core Brick Street Zone,” and may be given a budget to uncover some brick streets over the next 20 years, “after a successful demonstration project.”

Brick streets good or bad?

What? Not a fan of brick streets. Well, you are not alone. Some folks decry the bumpy ride they provide, while others point to that same rumbling road as a good thing. A city document cited a case study of Winter Park, Florida that showed traffic fell on one of the main brick streets by nearly one-third from 8,500 to 6,000 cars ,with the average speed taking a nosedive from 41 mph to 29 mph after a 1996 brick street restoration. That’s called traffic calming and it can be a good thing or a bad thing depending on your perspective.

Others complain that spending money fixing or uncovering brick streets is a waste just for the sense of place and historic ambiance. That view is countered, of course, by those who say brick streets can save money in repaving costs.

But whether you are for or against brick streets, here’s a chance to learn more for free and find out why you might want to care about the part of the brick street you can’t see.