Last spring, a facility manager in Fishers called us in a panic. A wheelchair user had tipped forward going down a curb ramp at their office park. The ramp looked fine from a distance—fresh concrete, yellow pads—but the slope was way too steep. Turns out, the previous contractor never checked the grade before pouring. That ramp failed every single ada curb ramp requirement you can think of. And the property owner got hit with a complaint, and a fix-it-or-else notice from the city. We tore it out and did it right. Here's what you need to know before you end up in that spot.
What Are Curb Ramps and Why Do They Matter?
A curb ramp is the sloped section between a sidewalk and a street or parking lot. It lets wheelchairs, walkers, strollers, and delivery carts get from one level to another without hitting a 6-inch wall. In Indianapolis, any accessible route that crosses a curb at a pedestrian crossing, accessible parking stall, or building entry has to have a compliant ramp. If you have accessible parking, the path from the stall to the front door might cross a curb—that crossing needs a ramp. No ramp, no compliance. And in a city with plenty of lawyers and ADA advocates, that's a risk you don't want.
ADA Curb Ramp Requirements: The Numbers You Need to Know
These numbers come from the 2010 ADA Standards and the newer PROWAG (Public Right-of-Way Accessibility Guidelines). Indianapolis follows those, plus local DPW and INDOT details. Here's the short version, in plain English.
Running Slope and Cross Slope
The running slope (front-to-back) can't be steeper than 1:12. That means for every 12 inches you go forward, you can only drop 1 inch. If your curb is 6 inches tall, you need a ramp at least 6 feet long—but you also need a level landing at the top, so the total footprint gets bigger. Many older parking lots have curbs that are 7 or 8 inches, so the ramp has to be longer. If your grade is too tight, you can use a parallel ramp or a combination ramp to make it work.
The cross slope (side-to-side tilt) can't exceed 1:48. That's about a quarter inch drop across 12 inches. Too much tilt and a wheelchair user has to fight to stay straight—they drift toward the curb or the traffic lane. We check this with a digital level on every single job.
Width and Landings
A curb ramp needs a clear width of at least 36 inches, not counting the flared sides. That gives a wheelchair or scooter enough room to pass. At the top of a perpendicular ramp, you need a level landing at least 36 by 36 inches. That's the flat spot where someone can stop, turn, or open a door without rolling backward. If you have a door swinging out onto the landing, you need more space.
Flares and Side Slopes
Where pedestrians could cross the sides of the ramp, those side slopes (called flares) can't be steeper than 1:10. If the flare is too steep, a wheelchair can tip over sideways. On many Indianapolis office park retrofits, we see flares that are nearly vertical—big problem. We regrade them to a gentle slope.
Detectable Warnings (Truncated Domes)
You need truncated domes—those bumpy yellow or brick red pads—at the bottom edge where the ramp meets the street or parking lot. They have to be 24 inches deep and span the full width of the ramp. They give a tactile warning to people with low vision that they're entering a vehicle area. In Indiana, cast-in-place domes hold up way better than surface-applied stickers. Stickers pop loose under snowplows and create a trip hazard. We install them right into the wet concrete.
Transitions and Vertical Lips
The bottom of the ramp has to be flush with the asphalt or gutter. No vertical lip over 1/4 inch (or 1/2 inch with a bevel). Any bigger and a caster wheel catches, a cane tip snags, or a snowplow blade catches the edge and chips the concrete. We saw cut and grind the adjacent asphalt to make a smooth tie-in.
Ramp Types and Site Conditions in Indianapolis
Not every site can fit a standard perpendicular ramp. In older neighborhoods near downtown or in places like Broad Ripple, sidewalks are narrow and grades are all over the place. A parallel ramp runs along the curb line, dropping the sidewalk level down to street level over a longer distance. They work well when the sidewalk is tight or the curb is high. Combination ramps are a mix—they turn a corner and drop at the same time. We've done plenty of parallel ramps along Monon Trail crossings in Carmel and Zionsville.
Drainage is a constant fight here. Freeze-thaw cycles will crack a ramp that holds water. We set the crossfall so water runs to the gutter, not puddling at the bottom. We also check nearby storm inlets—if the ramp blocks the gutter flow, you'll get a skating rink in January. And snowplows? They'll chew up a ramp that sticks up or has a rough edge. We design edges to be flush and use air-entrained concrete with a broom finish.
Retrofitting Existing Curbs: What to Expect
You don't always have to tear out the whole sidewalk. We can saw cut the curb, pour a ramp within the curb return, and tie into the existing concrete with dowels. The base under the ramp has to be solid—compacted aggregate, sometimes with geotextile fabric if the soil is soft. We wrote a whole post on aggregate base for parking lots if you want the details. The concrete mix matters too: 4000-4500 psi air-entrained mix for freeze-thaw, broom finish for slip resistance, saw cuts for control joints so cracks happen where we want them, not randomly.
For the tie-in to asphalt, we follow the same principles as our asphalt paving thickness guide. The transition from asphalt to concrete has to be solid or you'll get a lip over time. And if snowplow damage is a worry, check out our post on snow plow damage to curbs and striping.
Permitting? If the ramp is in the public right-of-way, you need an Indianapolis DPW permit and sometimes a maintenance-of-traffic plan. Along state routes, INDOT gets involved. We handle all that paperwork—you just sign the forms and we coordinate the inspections. We also keep at least one accessible route open during construction so your tenants can still get in and out.
What We Do at PavementPros
We're not just a concrete crew. As a general contractor for commercial properties, we handle the whole process: on-site grade checks, layout options, drainage review, drawings, permits, concrete, domes, and coordination with your striping contractor. We've done ramps at medical offices in Avon, retail centers in Greenwood, and apartment complexes in Plainfield. We see the same failures over and over: over-steep slopes, ponding at the gutter, loose surface-applied domes, and abrupt joints at the asphalt. We fix those.
We give you a written plan with specs—ramp type, concrete mix, base details, detectable warning details, traffic control if needed. No vague bids. And we schedule pours to minimize down time—usually the ramp is blocked off for a day or two, then you can drive over it once the concrete reaches strength (about 7 days for full load, but we'll tell you when).
Get a Compliant Ramp Before It Becomes a Problem
If you have a curb ramp that looks steep, has cracked edges, missing domes, or water pooling at the bottom, don't wait for a complaint or a lawsuit. The cost of a retrofitted ramp is a lot less than the cost of defending an ADA claim. And fall is the perfect time in Indianapolis—the concrete cures well in cooler weather, and you'll be ready for winter.
We'll come out, measure your grades, check your drainage, and give you a fixed, itemized proposal. No pressure, no sales pitch. Book a site assessment here and we'll get you on the schedule.
Ready for a free lot assessment?
We walk the lot, photograph the problems, and hand you a written plan — no pressure, no obligation.
