Metroped Inc - P.O. Box 7244 -  Alexandria, VA - 22307-0244   - Phone  202-747-6031
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Stone & Brick Surfaced Sidewalks 
Homeowners Can't Ignore Sidewalks
Washington Post Oct 11, 2003; Page F01
Discussions with the ADA Information Center
Discussion with the National Park Service


Stone & Brick Surfaced Sidewalks

Many sidewalks have a brick or decorative stone-face surface.  If the pebble used in the stone-face aggregate is small, [~10mm],   it presents minimal impact for any category of pedestrian use.   Used at wheel-chair ramps,  the texture provides a tactile change of benefit to the blind.


Unfortunately,  it costs less to use large (20-30mm) stones.   This results in a significantly rougher surface.   In time the cement binder wears, producing a 'tooth-like' protrusion better described as cobblestone. People using walkers tend to slide more than lift which is difficult on an uneven surface.   

'Walkers' with wheels work no better.  Their small wheels catch easily on any irregularity. After a few 'freeze-thaw' cycles stones break away adding small craters next to protruding pebbles.    These surface irregularities challenge pedestrians dependent on mechanical assistance.   Sidewalks using new bricks go through a comparable life-cycle.  As installed they are smooth.

Inevitably the sidewalk is ruin by the large trucks of utility and grounds maintenance crews.   Winter forces add to the toll.   Within a few years uneven brick edges catch the unwary.  


As the cement recedes from large stone aggregate,  the smooth surface of the pebble becomes the only surface a pedestrian's shoe contacts.   This surface, smoother than plain concrete, provides little traction, especially when wet.

ADA Accessibility Guidelines

These decorative surface types may be ADAAG A4.5.1 compliant as installed, but if examined many clearly would fail ADA muster mid-way through their life-cycle.

With little fear that that surface will be tested before acceptance, it appears that some Contractors might be using aggregate that is non-compliant as installed.

ADA Accessibility Guidelines (ADAAG). 

A.4.5 Ground and Floor Surfaces.

A4.5.1 General. People who have difficulty walking or maintaining balance or who use crutches, canes, or walkers, and those with restricted gaits are particularly sensitive to slipping and tripping hazards. For such people, a stable and regular surface is necessary for safe walking, particularly on stairs. Wheelchairs can be propelled most easily on surfaces that are hard, stable, and regular. Soft loose sand or gravel, wet clay, and irregular surfaces such as cobblestones can significantly impede wheelchair movement.

Source: Americans with Disabilities Act Accessibility Guidelines - Bulletin #4 Surfaces

Cosmetic Counter Argument

Ironically as stone-face surface crumbles,  the stone-face sidewalks appearance becomes scarred long before being replaced.   Adhesion problems make interim patching difficult.  Where tried, the new surface often is a mismatch of texture and color.

The photo location is 12th & Pennsylvania Ave, less then a half mile from the White House.  The esthetic repair incentive is as high in this area as it will be anywhere. 

Fortunately, historically old brick sidewalks do not present this problem.  The look rustic and brick edges have worn smooth presenting less problem to the mobility challenged.

Homeowners Can't Ignore Sidewalks

By Ann Cameron Siegal
Special to The Washington Post
Saturday, October 11, 2003; Page F01

Often there is no safe way to get around them -- the cracks, mounding, gouges and overgrowth that can make sidewalks hazardous.

When someone trips, stubs a toe, twists an ankle or has trouble maneuvering a wheelchair or walker, the question arises: "Who's responsible for this?"

If a public sidewalk abuts your property, you are. A property owner's responsibility goes beyond keeping sidewalks free of snow and ice. A property owner also is expected to take an active role in preventing sidewalk accidents by performing basic maintenance and by alerting local authorities to possible hazards.

Basic maintenance is largely common sense. Regular sweeping keeps grass, leaves and other debris from accumulating, thus avoiding slipping hazards. In addition, grass and weeds should be prevented from growing between bricks or concrete sidewalk panels and along the curb lines. Such vegetation hastens the deterioration of walkways and gutters.

And don't just look down. Robert A. Brubaker, director of Metroped Inc., an Alexandria-based advocate for walkers, devotes part of his Web site ( to pedestrian hazards that are "seldom addressed," including overhanging branches and overgrown shrubs. Plants that encroach on walkways can be just as hazardous as surface problems because they can force pedestrians to step into the street to avoid scrapes and scratches.

Shrubs and branches should be cut back to the property line. Municipalities have various rules that cover such plants. In Laurel, for example, the code dictates that overhanging branches must be at least seven feet above the sidewalk.

In Alexandria, if city crews have to come out to trim a homeowner's plants, the cost goes on the homeowner's tax bill, said Brett Sweeney, head of maintenance in the city's Department of Transportation and Environmental Services.

It may seem obvious what constitutes a tripping hazard, but municipalities have very precise definitions. In Alexandria, for example, a hazard is any deviation in grade of 1 inches, or any depression in which a high-heel shoe could get caught.

In Laurel, Teddy R. Dulaney, the director of public works, said that only a -inch deviation in grade or any crack more than an inch wide requires a repair. One square foot of spalling -- when the top layer starts to crumble -- will also put a sidewalk section on the list for replacement.

In the District, there are no specific definitions. Tripping hazards are decided case by case, said Bill Rice, spokesman for the D.C. Transportation Department.

"We encourage people to call our citywide call center whenever they see something that is a problem," Rice said. The report is supposed to be logged; callers get tracking numbers to monitor the progress of repairs. (The call center number is 202-727-1000.)

Montgomery County's Department of Public Works and Transportation Web site ( has a calendar detailing when subdivisions are scheduled for sidewalk repairs. The site also reports repair progress.


Trees and Tree Roots

Tree-lined streets are attractive, but tree roots are a common cause of tripping hazards. The biggest culprits are trees planted between sidewalks and curbs -- an area referred to as the utility strip because that's where power lines and telephone poles are located. There's little room there for roots to grow, so they go hunting for space, water and nutrients. They can grow horizontally about 18 inches below the surface, buckling sidewalks in the process.

In Wellesley, Mass., trees are not allowed in utility strips because of the lack of proper growing conditions, the possibility of damage by vehicles and because "trees actually provide better shade when set back from the road," according to the town's Web site.

Developers in Alexandria are experimenting with new measures to give roots near sidewalks more favorable growing conditions. In the Carlyle development, for example, continuous soil-filled underground tree troughs, parallel to the curb, allow roots to expand more than in traditional 4-by-6-foot wells.

At the Samuel Madden Homes, a former public housing project that is being redeveloped into mixed-income townhouses, a hybrid tree well is being tried. It combines features of the tree trough with a cantilevered well around three sides of the tree. Jeff Farner of the Alexandria Planning and Zoning Department said the goal is to maintain the sidewalks for pedestrians while providing tree roots as much soil as possible.



In Alexandria, about 2,000 linear feet of brick or concrete sidewalk are repaired or replaced each year. Tripping hazards get priority.

On a recent Friday afternoon, when a two-inch differential in height between adjoining concrete sidewalk panels in Alexandria's Del Ray neighborhood was reported, the city sent a repair crew within an hour. The workers applied a temporary cold-asphalt patch.

Such a rapid response is not always possible, city maintenance chief Sweeney said, but "once we are aware of a problem, we have 72 hours to respond, but try to take action within 24 hours."

Rice, in the District, said temporary repairs are made within a week and the city tries to permanently resolve each problem within 25 days.

The cost of repairing or replacing sidewalks is usually included in municipal budgets. Damage from age, cracks and tree roots is expected.

The District once required homeowners to pay half the cost of installing new sidewalks because they were considered property improvements. The city dropped that requirement last year, Rice said.

In Anne Arundel County, however, homeowners can be directed to "grade, lay out, pave, repave, construct, reconstruct, repair, extend, widen, straighten, or improve" public sidewalks abutting their properties, at their own expense, when public safety and welfare are at stake.

Pam Jordan, the county's land-use spokeswoman, said that once the county is notified of a problem, "we have to notify the property owner to make repairs." The property owner has 30 days to comply, either by paying the county to do the work or by hiring a contractor. It costs about $6.25 per square foot to replace an existing sidewalk, Jordan said.

Exceptions to the policy of charging homeowners for repairs have been made in large communities where sidewalks were widely deteriorating. Jordan said a specially budgeted project repaired Glen Burnie's sidewalks without individual homeowners being assessed.

Schedules for permanent repairs depend upon variables such as weather, project backlog and funding.

Sidewalk materials and installation techniques play a key role in frequency of repair.

Brubaker, the Metroped director, said there are major problems with decorative stone-face surfaces that spall or break out in chunks as they age. Michael Haynes, a concrete technician for the city of Alexandria, said that sometimes disintegration in a concrete walkway is caused by too much water in the mix.

Brick sidewalks, while often considered more attractive, are also more expensive to install and more costly to maintain.

Sweeney said old brick walkways are less of a problem than newer ones because they are weathered and worn and the corners have rounded off.

Newer brick sidewalks pose more of a hazard because they are still settling.

"As soon as a corner kicks up, it's a tripping hazard," he said. Alexandria has a full-time crew monitoring and repairing the miles of brick sidewalks in the city.



Slips and falls are commonly litigated. In determining liability there are some basic questions: What or who created the problem? How long has the hazard existed? Has there been reasonable time to repair?

If the hazard is very obvious, such as a large crack or mound in a pathway, then the pedestrian is expected to use reasonable caution in avoiding it. Brick sidewalks are assumed to be uneven, so again, the pedestrian is charged with taking extra care.

Kevin Craiglow, spokesman for Nationwide Mutual Insurance Co., said it is in the best interest of homeowners to properly maintain and see to the repair of sidewalks bordering their property. While slips and falls are covered in most homeowners' policies, there is greater liability if the issue is neglect, he said.

In Laurel, code states that homeowners and the city are held accountable for such accidents, Dulaney said. But because the city maintains the sidewalks, homeowners are probably off the hook if they notify the city that there is a problem, he said.

The bottom line: Perform routine common sense maintenance and bring sidewalk hazards to the attention of the proper authorities.

"We can't know about every crack or low-hanging branch," said George McAndrews, Alexandria's assistant city attorney. "If we don't know about them, it's impossible to fix them."

2003 The Washington Post Company 

PDF Version (partial text but with photos)



Discussions with the ADA Information Center

To: "adainfo" <>
Sent: Wednesday, June 14, 2000 7:16 AM
Subject: Re: New ADA Sidewalk Problem

( Please Foreword to Alison Levy )

Dear Alison

A few weeks ago I asked 'ADAINFO for could help with a discussion I was having with the National Park Services Planning Office. You provided all
the text from ADAAG 4.5 This specification, and particularly the appendix A4.5.1, provided the information I needed. Thank you for you competent

In follow-up discussions with NPS, and now others, it appears that most organizations are not aware of the additional clarification in the Appendix. They appear to be mis-reading the specification, particularly 4.5.2.

I'm looking for the Office, or better the Person, who maintains (updates) the specification. I like to mention what I've found.

Thanks for you help

Robert Alan Brubaker 


Dear Mr. Brubaker,

As an information center, we are not allowed to advocate. However, I can provide you with information on the Americans with Disabilities Act (ADA and more specifically, the ADA Accessibility Guidelines (ADAAG) so you may first, determine if you believe there is a violation of the ADA, and second, decide if you want to file a complaint and send it to the U.S. Department of Justice at:
(800) 514-0301. Please note that the ADA does not cover areas funded solely by the Federal government. (You may want to contact Dept. of Justice for more information about Federal property.)

Ground surfaces are covered under the ADA Accessibility Guidelines (ADAAG). The
U.S. Access Board has the entire ADAAG available on-line. I copied the following excerpts for your reference:

4.5 Ground and Floor Surfaces.

4.5.1* General. Ground and floor surfaces along accessible routes and in accessible rooms and spaces including floors, walks, ramps, stairs, and curb ramps, shall be stable, firm, slip-resistant, and shall comply with 4.5.  4.5.2 Changes in Level. Changes in level up to 1/4 in (6 mm) may be vertical and without edge treatment (see Fig. 7(c) ). Changes in level between 1/4 in and 1/2 in (6 mm and 13 mm) shall be beveled with a slope no greater than 1:2 (see Fig. 7(d) ). Changes in level greater than 1/2 in (13 mm) shall be accomplished
by means of a ramp that complies with 4.7 or 4.8.

4.5.3* Carpet. If carpet or carpet tile is used on a ground or floor surface, then it shall be securely attached; have a firm cushion, pad, or backing, or no cushion or pad; and have a level loop, textured loop, level cut pile, or level cut/uncut pile texture. The maximum pile thickness shall be 1/2 in (13 mm) (see Fig. 8(f)). Exposed edges of carpet shall be fastened to floor surfaces and have trim along the entire length of the exposed edge. Carpet edge trim shall comply with 4.5.2.

4.5.4 Gratings. If gratings are located in walking surfaces, then they shall have spaces no greater than 1/2 in (13 mm) wide in one direction (seeFig. 8(g)). If gratings have elongated openings, then they shall be placed so that the long
dimension is perpendicular to the dominant direction of travel (see Fig. 8(h)).

ADAAG Appendix:

A4.5 Ground and Floor Surfaces.

A4.5.1 General. People who have difficulty walking

or maintaining balance or who use crutches, canes, or walkers, and those with restricted gaits are particularly sensitive to slipping and tripping hazards. For such people, a stable and regular surface is necessary for safe walking, particularly on stairs. Wheelchairs can be propelled
most easily on surfaces that are hard, stable, and regular. Soft loose surfaces such as shag carpet, loose sand or gravel, wet clay, and irregular surfaces such as cobblestones can significantly impede wheelchair movement.

Slip resistance is based on the frictional force necessary to keep a shoe heel or crutch tip from slipping on a walking surface under conditions likely to be found on the surface. While the dynamic coefficient of friction during walking
varies in a complex and non-uniform way, the static coefficient of friction, which can be measured in several ways, provides a close approximation of the slip resistance of a
surface. Contrary to popular belief, some slippage is necessary to walking, especially for persons with restricted gaits; a truly "non-slip" surface could not be negotiated.

The Occupational Safety and Health Administration recommends that walking
surfaces have a static coefficient of friction of 0.5. A research project sponsored by the Architectural and Transportation Barriers Compliance Board
(Access Board) conducted tests with persons with disabilities and concluded that a higher coefficient of friction was needed by such persons. A static coefficient of friction of 0.6 is recommended for accessible routes and 0.8 for ramps.

It is recognized that the coefficient of friction varies considerably due to the presence of contaminants, water, floor finishes, and other factors not under the control of the designer or builder and not subject to design and construction guidelines and that compliance would be difficult to measure on the building site. Nevertheless, many common building materials suitable for flooring are now labeled with information on the static coefficient of friction. While it may not be possible to compare one product directly with another, or to guarantee a constant measure, builders and designers are encouraged to specify materials with appropriate values. As more products include information on slip resistance, improved uniformity in
measurement and specification is likely. The Access Board's advisory guidelines on Slip
Resistant Surfaces provides additional information on this subject.

Cross slopes on walks and ground or floor surfaces can cause considerable difficulty in propelling a wheelchair in a straight line.

A4.5.3 Carpet. Much more needs to be done in developing both quantitative and qualitative criteria for carpeting (i.e., problems associated with texture and weave need to be studied). However, certain functional characteristics are well
established. When both carpet and padding are used, it is desirable to have
minimum movement (preferably none) between the floor and the pad and the pad and
the carpet which would allow the carpet to hump or warp. In heavily trafficked areas, a thick, soft (plush) pad or cushion, particularly in combination with long carpet pile, makes it difficult for individuals in wheelchairs and those with other ambulatory disabilities to get about. Firm
carpeting can be achieved through proper selection and combination of pad and carpet, sometimes with the elimination of the pad or cushion, and with proper installation.

Carpeting designed with a weave that causes a zig-zag effect when wheeled across
is strongly discouraged.

I hope this is helpful information to you. If you have more questions, feel free to contact our office at: (800) 949-4232 V/TTY.

Alison Levy
Technical Assistance Specialist
ADA Information Center for the Mid-Atlantic Region

Discussion with the National Park Service Design Center

Subject: NPS Handicap Planning

I'm looking for the Office, or the Individual, within NPS who is the Advocate for Handicap Concerns with respect to Park Planning.

NPS for some years has been using a 'stone-face' surface on many of it's sidewalks. Some of these sidewalks use small stones and are almost as smooth as concrete. Others have a surface with fairly large stones imbedded. The large stones produce a surface which is not smooth. It can be felt through shoes. This weekend I saw my second occurrence of a person using a 'walker' having trouble getting it to move on a Park sidewalk that had this 'large-stone' surface. It was near the FDR Monument in Wash DC. The 'walker device' had small wheels and the person using it was humped over it, having trouble trying to push it along. The small wheels on the walker seemed to be catching on the protruding stones. 
Source: Robert A. Brubaker Email dtd Date: 5/16/00 8:14 AM


Bob, what a timely question. NPS is currently working on a comprehensive approach to universal design. I will send this on to Susan Spain, who is the coordinator for the Denver Service Center.
Source Email from N.C. at NP-DENVER dtd 5/16/00 8:51 AM


I've just returned from 2 weeks on the road, so let this note document my hearing from you and give me a chance to make a meaningful reply after I've
had a chance to catch up. Interestingly enough, I was down in Asheville, NC, last week and one problem there is the slate floor in the new HQ building. People are tripping on infinitesimal differences in the surface; we are trying to determine the best solution at this point.

Source Email from N.C. at NP-DENVER dtd Monday, June 12, 2000 9:05 AM