Although curb ramps have been around since 1973 (McMillen, 2000), it was the Americans with Disabilities Act of 1990 (ADA) law that made the curb ramp a part of everyone’s life. The ADA is a civil rights legislation designed to provide a certain level of accommodation for individuals with a disability to take part in society. In providing this level of accommodation, technical guidelines where drafted into what is known as ADA Accessibility Guidelines (ADAAG) for Buildings and Facilities. Standards have been put in place for the various components of curb ramps (location, slope, depth, width, and obstructions). However, implementing the new standards has problems due to the following:

1. Existing conditions and funding constraints may not allow for all standards to be implemented.

2. The lack of funding may not allow improving accessible access if all the standards are required.

3. Implementing all the minimum standards for the various ramp components may still result in unsafe travel for individuals with physical disabilities.

4. Lack of quality design and construction of ramps may minimize the value of the funding that goes into actual ramp construction.

The above problems may result in delaying access to the individuals with physical disabilities. It has been identified that the current "cookie cutter" standards for ramp components needs to be upgraded to create an accessible and safe environment. The Architectural and Transportation Barriers Compliance Board is working towards a better solution. The objective of this paper is to develop a solution that will optimize the value of the funding of accessible access ramps.

The elements of ramp accessibility requirements are covered in Section 4.7, Curb Ramps, of the ADAAG. The specifications include the following subsections:

4.7.1 Location - shall be provided wherever an accessible route crosses a curb.

4.7.2 Slope - Maximum slopes of adjoining gutters, road surface immediately adjacent to the curb ramp, or accessible route shall not exceed 1:20.

4.7.3 Width - The minimum width of a curb ramp shall be 36 in (915 mm).

4.7.4 Surface - Surfaces of curb ramps shall comply with all other requirements.

4.7.5 Sides of Curb Ramps - The maximum slope of the flare shall be 1:10.

4.7.6 Built-up Curb Ramps - Built-up curb ramps shall be located so that they do not project into vehicular traffic lanes.

4.7.7 Detectable Warnings - [Provision suspended until July 26, 2001]

4.7.8 Obstructions - Curb ramps shall be located or protected to prevent their obstruction by parked vehicles.

4.7.9 Location at Marked Crossings - Curb ramps at marked crossings shall be wholly contained within the markings.

4.7.10 Diagonal Curb Ramps - If diagonal (or corner type) curb ramps have returned curbs or other well-defined edges, such edges shall be parallel to the direction of pedestrian flow.

4.7.11 Islands - Any raised islands in crossings shall be cut through level with the street or have curb ramps at both sides and a level area at least 48 in (1220 mm) long between the curb ramps in the part of the island intersected by the crossings.

The information provided in the above guidelines does not integrate all the factors that may be required to provide safe handicapped access. Designers have difficulty understanding what items are to be integrated because of the incomplete requirements and limitations due to funding and then must translate and communicate the solution through drawings and specifications to contractors who are bidding the lowest possible price. The problem designers are faced with is the objective of their design. Is it to 'install accessible access ramps' or 'make the area under renovation accessible and safe for accessible access?' An example of this is found in the following case, "Curb ramps mid-block along Anderson Lane have a bad angle (Walk Austin, 1998)." In addition, there are sidewalks that lead to a dead-end or crosswalks that lead to middle of the sidewalks. Other problems include large and small gaps in sidewalks, depressions in pathway, and parking lots and drives being used as access paths along Anderson Lane. (www.io.com)

Another problem in designing the integration of the components is interpreting the requirements. The U.S. Architectural and Transportation Barriers Compliance Board (2001) has produced guidelines for the U.S. Access Board. Examples include:

1. The grade break between the counter slopes of gutter and/or road surfaces within 24 inches of the curb ramp and the running grade of the curb ramp shall not exceed the algebraic difference of 11 percent.

2. If two or more plane changes are present, they shall be separated by 24 inches (455 mm).

It raises the following question: Is the total of 24 inches measured from the bottom portion of the curb ramp or just the portion the touches the bottom of the curb ramp to the maximum length of 24 inches be it the gutter or the road? Besides the number of factors to take into account in designing and constructing a curb ramp, the designer must also take into account the maneuverability of the wheelchair user and the numerous styles of mobility devices (USATBCB, 1999).

The designer is faced with the following challenges:

1. Identify the 'best value' for safe accessible ramp access.

2. Ensure that the 'best value' meets all current standards.

3. Ensure that the safe access to the ramp is not minimized to other existing obstacles in the surrounding environment.

4. Accurately estimate the construction cost to include as many modifications as possible to ensure safe access.

5. Ensure that the quality of construction does not minimize the safe access.

Figure 1 shows the traditional construction delivery system. The source of the majority of problems occur in the identification of scope (requirements and level of funding.) The design (communication of the scope) causes further misunderstandings. The competitive bid process, which forces the contractors to bid the lowest possible price to meet minimum requirements, magnifies any problems caused by incorrect scope or insufficient design. The award of construction based on the 'low-bid' creates the following problems for designers:

1. Transforms a communication document, which shows intent to a regulatory document which, describes the means and methods and final product constructed 'in-place.' If it is not written, it will not be done, if it is wrong, it will still be constructed, unless the designer identifies the error.

2. Ignores the experience and high quality of performing contractors, who transform the design and specifications into a constructable and performing product. Instead it gives the advantage to non-performing contractors who can turn in a lower price using less performing craftspeople, construction mangers, and critical subcontractors and materials.

3. Brings liability to the designer due to the inability of the low bidder to correct mistakes because of construction inexperience or need to process change orders. Low bidding contractors do not have the motivation to produce high performance construction. This creates an adversarial environment, increasing the designer’s liability.

4. Increases the overall price and lowers the quality of the construction, reducing the amount of total construction funding.

5. Creates an inefficient process, forcing designers to deal with construction problems and costs, identifying requirements that may not be the 'best value' (construction solution and price.)

6. Forces the designer to work without the benefit of the assistance of performing contractors.

The process would be assisted with the following modifications:

1. Identifies the 'best value' construction of curb ramps considering price and safe access for individuals with disabilities.

2. Minimize the adversarial environment by allowing the designer to partner with performing contractors, without forcing contractors to do much more work than in the low-bid process.

3. Minimize the decision-making and risk of the designer by waiting for information by getting the input of performing contractors on alternatives and prices.

4. Allows the 'best value' within the budget to override 'cookie cutter' requirements to maximize safe handicapped access.

The federal government is moving toward performance based contracting. (FARS Directive.) The performance based contracting process assists the designer in increasing contractor performance. A successfully tested performance based contracting process is the Performance Information Procurement System (PIPS.) (Kashiwagi, 2001) This process is shown in Figure 2. The process brings the following advantages:

1. Allows the designers to communicate intent.

2. Allows designers to be creative in meeting the requirements.

3. Allows the designer to identify the best performing contractor, and partner with the contractor to optimize the value of the design before construction.

4. Allows the identification of the 'best value' of the accessible access ramps and surrounding areas.

PIPS differs from the traditional low-bid process and other best value processes by (Kashiwagi, 2001):

1. Uses an artificial intelligent processor (modified Displaced Ideal Model, Zeleny, 1985) that takes performance differential without translation to prioritize the options.

2. Uses past performance of key construction personnel (site superintendent and project manager) and critical subcontractors to select the best value.

3. Forces the contractor to identify the risk of nonperformance (price, schedule, and quality) and how they will minimize the risk.

4. Allows the contractors to value engineer the project in terms of performance from the viewpoint of the constructor.

5. Allows a preaward period, where the top prioritized contractor, designer, and user do the following:

   1. Have a full technical review.

   2. Address construction value engineering ideas that bring value based on innovative construction methods or materials.

   3. Partner to identify the 'best value.'

There are two major locations in PIPS where the best value of accessible access and ramp construction can be optimized are:

1. When alternatives are being prioritized, use accessible access value engineering and options as a selection criteria of best value.

2. The preaward period which is used to recheck, implement value engineering of the contractor, and partnering to optimize the design and construction.

The accessible access 'best value' can be rated on the differential of the options using the following performance criteria:

1. Value engineering to increase accessible access while minimizing the cost

2. Identification and minimization of risk to handicap safety

3. Maximum change of direction

4. Visibility of ramps

5. Space for maneuverability

6. Change in levels

Table 1 shows additional factors, which can measure the performance of the construction quality of the curb ramps.

The accessible access can either be a major or subcategory of prioritization and selection. Table 2 shows a potential weighting of criteria. It is important to note, that even though the prioritization will be affected by differential of construction quality, the project requirements have to be met. Value engineering is given credit in the contractor’s proposal. After the prioritization is made by the artificial intelligent processor, the contractor prioritized as the 'best value' enters a preaward period that allows partnering between the user, designer, and contractor, implementation of proposed value engineering ideas, and clarifying the specifications and drawings. The preaward period allows the designer to be far more effective in delivering safe accessible access than in the scope and design phase when information is lacking on construction options, prices, and quality.

The implementation of a best value or performance contracting process allows a more innovative approach to the design and construction of accessible access ramps. It provides the following:

1. Identifies the best available option to provide accessible access.

2. Provides a partnering environment between the user, designer, and best performing contractor minimizing the adversarial environment of the low-bid environment, which requires rigid cookie cutter standards.

3. Minimizes the need for designers to make decisions early in the process when all the construction information is not available.

4. Maximizes the safety of accessible access without the need for more inflexible standards.

This study recommends that the need and type of standards be reviewed in light of the advantages of performance based contracting to find the 'best value' solution. This study recommends that pilot projects be initiated to test the concepts of this paper.

ADA Accessibility Guidelines for Buildings and Facilities, Federal Register, Vol. 56, No. 144. pp. 35632-35633.

Federal Acquisition Regulations System (2001). Performance-Based Contracting.

Kashiwagi, D. T. (2001) Information Management Theory, 4^th Edition, Tempe: PBSRG.

Kizzire, J. (July 21, 1997). The Birmingham Post-Herald. Obstacle Course: Paraplegic strives to make city accessible. www.adanet.org/spencer.htm.

McMillan, B. (2000). www.walkinginfo.org/de/disability/mobility/index.htm. Part of Pedestrian and Bicycle Information Center.

Tam, K. (Feb. 3, 1998). The Daily Californian. More Curb Cuts for City’s Disabled. www.dailycal.org/archieves/98/2/3/ramps.html.

U.S. Architectural and Transportation Barriers Compliance Board. (January 10, 2001). Building a True Community Final Report for the Public Rights-of-Way Access Advisory Committee. www.access-board.gov/prowac/commrept/index.htm.

U.S. Architectural and Transportation Barriers Compliance Board. (November 1999). Accessible Rights-of-Way: A Design Guide. Section 3.4.2 Curb Ramp Usability Considerations. www.access-board.gov/publications/PROW%20Guide.htm#3_4_2.

Walk Austin (2000). Pedestrian Problem Data Base, Pedestrian Problem Report Form. www.io.com/~snm/walk/problems/prob5/anderson.html.