“In Texas, you need shade trees, or people are not going to be walking,” says Humberto Rey, an urban designer with the City of Austin. Rey is the coordinator for Austin’s Great Streets program, an initiative designed to make Austin a place where “streets are for people.”
The goal is to redefine the right-of-way (ROW) in downtown Austin, and make it less car-oriented and more balanced with various modes of transportation, especially walking. In the past, 75 percent of the typical 80-foot ROWs in downtown Austin was dedicated to vehicular traffic. Rey says the new standard is for a minimum of 45 percent of the ROW to be used for sidewalks. That equates to 18 feet for each side of the street, for which the city has developed a series of design standards—covering everything from benches to trash receptacles—that create a unified look downtown and encourage an animated streetscape.
The Paver-Grate allows for paving over the tree’s soil area while passing stormwater runoff into the roots but staying resistant to clogging.
IRONSMITH, a company in Southern California that manufactures high-grade iron, aluminum, and steel products from recycled materials, has been a key player in Austin’s streetscape renewal. They manufacture tree grates, tree guards, and bollards, among other things—products that only landscape architects and urban designers notice but that form the backbone for high-quality streetscapes.
Its flagship product—which Austin has become a showcase for—is the Paver-Grate, a suspended paving system that allows pavers to be installed over the planting soil around street trees, widening the walkable area of a sidewalk significantly. “Trees need a certain amount of uncompacted soil,” says Brian Vavrina, IRONSMITH’s Texas sales representative, “and Paver-Grates provide that without sacrificing space for pedestrians.” It’s a win-win that has made Paver-Grates popular among designers.
Paver-Grates also are not susceptible to getting clogged with trash like conventional tree grates and allow stormwater runoff to filter through to the root zone, making any paver a permeable one.
Typically manufactured as six-by-six-foot modular panels, Paver-Grates can be placed end-to-end along the curb, creating a continual trough of engineered soil for street trees. “A concrete foundation is poured along the perimeter to support the Paver-Grates above the soil, and the pavers are then laid over the top,” Vavrina says. It’s an approach that makes the product completely invisible to pedestrians. Typical metal tree grates are a walkable surface in theory, but veteran designers know that people unconsciously avoid them.
“[The Great Streets program] specifies either tree grates or Paver-Grates for tree plantings along our most urban streets,” Rey says, “but tree grates can shift. So, we prefer and encourage using Paver-Grates.”
Austin’s initiative has supported the makeover of more than 100 block faces so far and, as a result, has made Austin developers some of IRONSMITH’s biggest clients. In the Texas heat, a tree-friendly street is a pedestrian-friendly street. By stacking the functions of healthy trees and sidewalk circulation into one space, Paver-Grates have proven themselves a design-friendly solution to a perpetual urban challenge.
