Contractors have been busy in southwest Mesa this month knocking out old ramps and replacing them with “truncated domes,” which give the visually impaired a tactile warning that they’re about to enter the street.

Mesa’s total bill for replacing or retrofitting sidewalk ramps, covering nine street overlay projects since 2006, is expected to reach slightly over $2 million, according to a report from city engineer Elizabeth Huning.

In total, the project will cost $24 million and call for 1,240 ramps to be rebuilt and an additional 226 retrofitted.

Rene Powell, a marketing and communications specialist in Mesa’s transportation department, stated the following issues that designers have come across. “They’ve revised them so the domes have a pattern so the walkers and wheelchairs can go between the grooves,” Powell said.

Also, “Valley cities had to get together and work with the industry to develop a product that would stand the heat we have here in Arizona,” Powell said.

The sidewalks are built by RampDome Systems LLC, a Scottsdale construction company. The domes are made of yellow-dyed concrete, and should last between 15 to 20 years.