Author J. Steven Hunt
As an experienced safety consultant, I’m called to investigate a wide range of premises liability incidents. One common premises incident that often results in serious injury is a fall on a curb ramp. There are at least four types of curb ramps: flare side, parallel, returned curb and built-up. This post will focus primarily on flare side curb ramps which are the most common type constructed today.
Curb ramps were originally designed and incorporated into building means of egress is order accommodate handicapped individuals, particularly those in wheel chairs. A standard 6-inch curb can be a significant barrier for someone with impaired mobility. The International Code Council/American National Standards Institute ICC/ANSI) A117.1 Accessible and Usable Buildings and Facilities and the ADA Standards for Accessible Design provide guidance on the proper construction and placement of curb ramps.
Figure 1: An illustration of a properly constructed flared side curb ramp.
When assessing the safety of a flare side ramp slope, color contrast, lighting, pedestrian traffic and human factors are common areas to evaluate. In this post, I’ll discuss slopes on flared side curb ramps which is an area that I am often called upon to evaluate in the course of a fall investigation. While an excessive slope on a ramp can lead to a slip incident, the most common incident I investigate involves trip or miss-steps.
Figure 2: A view of a curb ramp in a publicly accessible pedestrian walkway with flares that do not conform to applicable codes and standards.
Codes and standards for curb ramps state, “Slope and Rise. The least possible slope should be used for any ramp.” There are two sections of a flared side curb ramp that have slope. The first is the incline in the center of the structure that is called the running slope. The slope for this section of the ramp should be no more than 1:12. 1:12 mean for every inch of rise the ramp should have 12 inches of run or length. Slope can be converted to percent grade or degrees for measurement purposes. The second section are the flares on both sides of the running slope center section of the ramp. The curb ramp standard calls for these flares to be a maximum slope of 1:10 when the sidewalk space at the top of the running slope of the ramp is 48 inches or more. However, if the space at the top of the ramp is less than 48 inches, a less steep slope of 1:12 is allowed. A 1:10 and 1:12 slope is a gradual gentle slope.
Figure 3: Close-up views of the ramp shown in Figure 2. The flared portion of the ramp is significantly steeper than allowed by the applicable codes and standards.
A properly built flared side curb ramp is designed to allow pedestrian traffic to walk across the ramp and to provide barrier free access to handicapped individuals. When a ramp has steep sections like the one shown in this blog, the potential for a trip or miss-step leading to a loss of balance and fall is increased.
J. Steven Hunt, CPCU, ARM, is the senior safety consultant at Warren. Steve, who specializes in premises liability incidents, construction falls and safety management programs, has achieved the designation of Associate Risk Management and Chartered Property and Liability Underwriter from Insurance Institute of America, Chicago, IL. Steve has investigated more than 1,000 accidents in his more than 35-year career, including 33 cases involving fatalities. He holds a Bachelor of Science in Administrative Management with a Minor in Occupational Safety and Health from Clemson University.
