The passenger platform level of service concept is used to evaluate the capacity and comfort of the rail platform. This concept is related to walking and waiting and is based on the freedom to select a desired walking speed and the ability to bypass slower-moving passengers. Other considerations related to passenger flow include the ability to cross a passenger traffic stream, to walk in the reverse direction of a major passenger flow, and to maneuver without conflicts with other passengers or changes in their walking speed.

The level of service is based on the available standing space, perceived comfort and safety, and the ability to maneuver from one location to another. Since the passenger level of service is based on the amount of passenger space available, the level of service thresholds can be used to specify desirable design features such as platform size, number and width of stairs and so forth.  Level of service is presented in terms of the average space per person.  The level of service required for waiting is a function of the amount of time spent waiting, the number of people waiting and the desired level of comfort.  The longer the wait, the greater the space per person required.  People do not accept being tightly packed on a train platform.

The best level of service is A. In this case, passengers are standing and free to circulate through the waiting area without disturbing others, with an average passenger area of greater than 13-square feet per person.  In  level of service B, passengers are standing with  partially restricted circulation to avoid disturbing others waiting, made possible by  an average passenger area of 10 to 13 square feet per person.  In level of service C, passengers are standing with restricted circulation through the waiting area, possibly disturbing others, and this density is within the range of personal comfort, with an average passenger area of 7 to 10 square feet per person.  In  level of service D, passengers are  standing without touching; circulation is severely restricted, and forward movement is only possible as a group; long-term waiting at this density is discomforting with an average area of 3 to 7 square feet per person.  In  level of service E, passengers are standing in physical contact with others; circulation is not possible; waiting at this density can only be sustained for a short period without serious discomfort, and the average passenger area is 2 to 3 square feet per person.  The level of service F occurs  when virtually all persons are standing in direct physical contact with each other; this density is extremely discomforting; no movement is possible; the potential for pushing and panic exists, and the average passenger area is less than 2 square feet per person.

To determine the number of passengers that are occupying a space is a complex matter requiring information from numerous sources.  One method for gathering this type of information is the time-space analysis, which considers the space occupied by a person and the time spent engaging in a specific activity within that space.  The space required for a particular activity is represented by the number of people involved in an activity, the space required for that activity and the time required for that activity. The level of service for an existing passenger rail platform is determined by the following method:

· Estimate the maximum passenger demand for the platform at a given time

· Measure the existing platform’s length and width

· Calculate the additional platform walkway width needed

· Determine the unusable platform areas

  o Calculate the waiting storage area required for exit/entrance points (stairs, escalators, and elevators) plus an 18 inch buffer zone.

  o Calculate the additional platform area that cannot be used, including dead areas and physical obstructions (add an 18 inch buffer zone to the physical obstructions).

  o Add a 24 inch buffer zone (tactile strip) for each platform edge for the entire platform length.

  o Add the width of any edge boards (rubbing boards) for the entire length of each platform edge.

· Calculate the total unusable platform area by adding the walkway width, waiting storage areas at exit/entrance points, dead areas, tactile strip area, edge board and buffer zones

· Subtract the unusable platform area plus the additional platform walkway width from the total usable platform area and divide by the maximum passenger demand.

If the results of this calculation are less than ten square feet per person, the platform would be considered overcrowded. Ten square feet per person (level of service B) is generally considered the minimum standard for queuing on a passenger rail platform.