ElevatorCalc

ADA Elevator Door and Signal Timing for Boarding

Published . Sources read . Written for architects, accessibility coordinators and elevator project planners.

An elevator boarding timing calculation needs a clearly defined start and finish. Under section 407.3.4 of the 2010 ADA Standards, the relevant interval begins with the specified notification and ends when the doors begin to close, giving a person time to reach the responding elevator. The mechanical duration of door closing and the door's kinetic energy are separate topics, outside the scope of this article. The calculation below is an educational planning check, not an instruction to adjust an elevator.[1]

Establish which requirements apply

Start by identifying the elevator type and the work under consideration. The Access Board's guide distinguishes section 407 elevators from limited-use elevators, private residence elevators, and platform lifts, and it explains that the scope of an alteration affects which requirements apply. Before a general calculation is treated as a project requirement, have the project accessibility professional establish the relevant scope.[2]

Write the scope at the top of the worksheet: building, floor, car identifier, control arrangement, applicable standards, and drawing revision. This suggested record format tells a reviewer which installation the calculation is meant to describe.

Use the specified distance and units

For the general case covered by section 407.3.4, the requirement can be written as the equivalent expression T = max(5, D / 1.5), with T in seconds and D in feet. The distance runs from a point 60 inches directly in front of the farthest call button controlling that car to the centerline of its hoistway door. The division uses a rate of 1.5 feet per second, and the result cannot be below 5 seconds.[1]

The published metric expression uses D in millimeters and a divisor of 455 millimeters per second. Whichever unit system you select, keep it explicit. A worksheet should not accept a distance in inches and then calculate as though the entry were feet.[1]

For review, place a simple annotated lobby sketch beside the input. Mark the reference point and the hoistway door centerline, then ask the responsible professional to confirm the measurement basis. Draw a new sketch of the actual project. Do not copy a standards illustration.

Work through illustrative estimates

Suppose the relevant distance is an estimated 12 feet, an invented figure for illustration rather than a measured lobby. Dividing 12 by 1.5 gives 8 seconds, so the formula returns 8 seconds. That result is the interval from notification to the start of door closing, under the stated assumptions.

For a second illustrative estimate, use a distance of 6 feet. The division gives 4 seconds, but the 5-second floor applies, so the formula returns 5 seconds. This is why the minimum belongs inside the expression, not in a note a reader might miss.

Keep the entered distance with the result, and do not round an actual minimum down. The example arithmetic does not establish that any layout, measurement, or elevator complies. A project review still needs the equipment classification, the notification sequence, and the applicable exception analysis.

Record the fully open delay separately

Section 407.3.5 addresses a different interval. After a car call, the doors must have a fully open period of at least 3 seconds. Give this check its own field instead of relabeling the whole boarding interval as fully open time. The two requirements describe different events, and each needs to be evaluated against the actual sequence.[1]

A review note might, for example, give one line to the calculated notification interval and another to the required fully open delay. Ask the specialist to explain how each is satisfied. Do not turn the two values into an assumed controller setting, and do not simply add them together without evaluating how their timing relates.

Check the exceptions before using a result

For an in-car lantern, the standards permit a specific starting event tied to the signal being visible from the defined lobby point and to the audible indication. Note this explicitly when describing the observed or proposed sequence. Section 407.3.4 also exempts destination-oriented elevators from its timing calculation, so applying the generic formula to those elevators without identifying that exception would misstate the requirement.[1]

The Access Board guide explains that destination-oriented systems have their own signaling provisions within section 407. Record the system classification and ask the responsible professional to confirm which review applies. Do not describe an exception to this one calculation as an exemption from elevator accessibility requirements in general.[2]

Ask for a documented review

Prepare a concise review package with the scope, source edition and sections, drawing, measurement, units, arithmetic, notification description, and unresolved questions. Then ask a qualified accessibility specialist and an appropriately licensed elevator professional to validate it against the actual equipment and the requirements administered by the authority having jurisdiction.

For an existing installation, report what the user experienced and identify the car and floor. Leave equipment testing and adjustments to authorized professionals. The Access Board also explains that pressing door close cannot shorten the applicable initial minimum timing, and that reopening-device duration is a separate requirement. Keep those issues distinct in the service request.[2]

ElevatorCalc has no door and signal timing calculator. The ADA car size checker covers a different part of section 407, the car's inside dimensions and door width, and it shows its working. Any result is preliminary education, not certification and not an instruction to adjust equipment. Before implementation, the responsible professionals must review the applicable licensed elevator safety standards, current manufacturer information, and project requirements.

  • ADA elevator car size checker: Checks an elevator car's inside dimensions and door width against the 2010 ADA Standards: passenger elevators (407.4.1), LULA elevators (408.4.1) and private residence elevators (409.3 and 409.4.1).

Sources

All sources read 2026-10-03. Standards edition: 2010 ADA Standards for Accessible Design. Clause descriptions and explanations are original paraphrases, with no reproduced standards tables or illustrations.

  1. U.S. Access Board, Chapter 4 Accessible Routes. Sections 407.3.4 Door and Signal Timing (with its exceptions for in-car lanterns and destination-oriented elevators) and 407.3.5 Door Delay. https://www.access-board.gov/ada/chapter/ch04/#407.3.4
  2. U.S. Access Board, Guide to the ADA Accessibility Standards, Chapter 4 Elevators and Platform Lifts. Required Compliance, Destination-Oriented Elevators, Existing Elevators, and Common Questions. Guide revision date not stated. https://www.access-board.gov/ada/guides/chapter-4-elevators-and-platform-lifts/