We Houstonians love our classic blue-and-white mosaic street signs. They show up on plenty of local pride merch, and some of us even commission our own tiles via Curb Appeal Blues. Yet directly ask a resident about the signage and most of us couldn’t tell you where it came from. Like mosquitoes, Mattress Mack, and refinery fires, the mosaics have always just kind of been here, a load-bearing pylon of the city’s familiar iconography. But, as with all things, they have a history, too. And quite a curious one at that.

“They’re a chapter in this really long story of how Houston basically marketed streets, which has to do with the city growing and paving streets, more people having cars, more people trying to figure out how to get around,” says Jim Parsons, programs director at Preservation Houston.

Discussions regarding how to mark Houston’s then-nascent street system began around 1903, in his estimation. However, the mosaics didn’t start dazzling local curbsides until around 1922, under the leadership of then-mayor Oscar F. Holcombe. The original designers’ names were lost to time, but Parsons theorizes that the familiar visuals likely came about more for the sake of construction logistics than an intentional aesthetic statement. He also points out that the choice of blue and white was indicative of infrastructural trends at the time, and believes that this stems from the combo’s comparative legibility and visibility.

The City of Houston initially experimented with vertical concrete street markers, painted black and white. A few remain, such as the one on Dunlavy near Westheimer or the restored examples in Southampton near Rice University. An attempt was made to use metal or painted wood signs as well, but these options encountered a major challenge: old-timey ne’er-do-wells.

“Neighborhood kids would either take the metal signs down or turn them so that they faced in the wrong direction to confuse people,” Parsons says. “And so the mayor was like, well, these tile signs will cut down on our juvenile delinquents messing with our street signs. So they started putting them in.”

This led to what he refers to as a “jumble of street signs” with no real unifying look—something not unfamiliar to contemporary Houstonians used to navigating the city’s eclectic architecture.

“You could apparently drive from neighborhood to neighborhood, and you never knew what kind of sign you were going to run into, if there was one at all, and a lot of them were in bad repair. The wood ones had faded, the metal ones had rusted, the tiles and the curbs would get torn up when they would do street work and they wouldn't get replaced,” Parsons says. “So we didn’t really start to get uniform street signs like we have now until the mid-1950s…the tiles are just a chapter in that long story.”

Unfortunately, as “just a chapter” rather than the final decision, the mosaics faded out of popularity over time. Parsons mentions that in 1956, the city started putting money toward standardizing the street signage, and by that point many of the mosaics had already deteriorated or disappeared.

It’s unknown how many mosaic street signs were originally commissioned. The Blue Tile Project, an initiative dedicated to chronicling and preserving the extant examples, as well as encouraging Houstonians to have their own installed, could not be reached for comment. Its website has also been taken down and replaced with a “Coming Soon” banner. However, Preservation Houston is also involved in helping individuals and neighborhood associations with keeping the tiles intact.

“People fell in love with them and started to see them as a symbol of Houston…The city considers them to be obsolete street markers, just like the concrete markers, too,” Parsons says. “The city is not going to officially do any maintenance on those, because the city’s official street signs [are] the metal ones that are on poles or hanging by traffic lights...so that’s why you see the blue tile markers disappearing.”

Preservation Houston occasionally receives calls from concerned citizens asking how they can rescue their street’s mosaics. Parsons and his team point them in the direction of Houston Public Works officials and coach them on how to ask construction crews to keep the signs in one piece when jackhammering down a curb. These either end up in private collections or reinstalled. Some also reach out to inquire about replacements for long-lost tiles, such as select streets in the Woodland Heights neighborhood.

“It’s an interesting reminder of the steps that we took in trying to figure out how to do something that nobody thinks about today,” Parsons says.