Understanding the Code Update on Unintended Car Motion

Elevator safety regulation is evolving — and one of the key areas now under formal regulation is protection against unintended or uncontrolled car motion (UCM). That’s when an elevator car moves away from a landing with the doors open or unlocked, or without a demand being called, due to a failure (brake, motor, coupling, control) or malfunction.

What are the relevant standards?

• ASME A17.1 “Safety Code for Elevators and Escalators” sets the baseline for new installations and major alterations.

• ASME A17.3 “Safety Code for Existing Elevators and Escalators” guides retroactive application and modernization of existing equipment.

• Local jurisdictions are adopting or amending these codes; for example, in ‎New York City there’s a specific requirement for existing traction elevators with single-plunger brakes to comply by January 1 2027.

  
  

What’s changing — key provisions for unintended motion

Here are some of the core new or updated requirements:

• Section 2.19 (“Ascending Car Overspeed and Unintended Car Movement Protection”) in ASME A17.1 includes a requirement that, upon detection of unintended car motion, an emergency brake must be applied to stop and hold the car with rated load, stopping within a limit (for example, max 1 220 mm / 48 in from landing sill to car sill) in both directions.

• If the detection means for unintended motion relies on electrical power, the loss of that power must itself trigger the emergency brake.

• Once actuated by unintended movement, the detection means must stay locked out until manually reset; the car must not start or run unless the detection means is reset.

• For existing installations, ASME A17.3 targets retro-active safety upgrades (including unintended motion devices) for older equipment.

• Specific to the NYC example: All existing traction elevators with single-plunger brakes must either be converted to dual-plunger brake assemblies or comply with an unintended car movement protection system by Jan 1 2027.

  
  

Why make this change?

• Single-plunger brake systems (common in older traction elevators) pose a potential safety risk: if that one brake fails, the car could drift or move away from the landing unexpectedly.

• Unintended motion while doors/gates are open (or unlocked) is a critical hazard — risk of entrapment, fall into the hoistway, unexpected acceleration or deceleration.

• The updated code aims to close that safety gap and ensure all vertical-transport systems are equipped with modern protection against this scenario.

  
  

What This Means for Your Building / Elevator Fleet

1. Inventory & Evaluation

• Identify all traction elevators (especially older units) and check whether they use single-plunger brakes or otherwise lack dedicated unintended-motion protection.

• Determine whether any local jurisdiction (city/state) has already adopted or will soon adopt the revised standards (e.g., NYC’s Jan 2027 deadline).

• Perform an assessment: Is your elevator already compliant, partially compliant, or out-of-compliance based on the new requirement?

  
  

2. Upgrade Scope Options

Depending on the evaluation, compliance may be achieved by one of two typical paths:

• Brake system retrofit/upgrade: Convert from single-plunger to dual-plunger brake assemblies.

• Install Unintended Car Movement (UCM) protective system: For example, rope-grippers on hoisting ropes, dedicated emergency brake devices, detection/trip circuitry.

Other factors: if you are already planning a broad modernization (machine, controller, ropes, cab) it may make sense to combine the UCM upgrade into that scope.

3. Timeline & Compliance Risk

• Deadlines (such as Jan 1 2027 in NYC) mean the time to act is now. Delaying could result in permit issues, non-compliance citations, elevated risk, and higher costs.

• Lead times for equipment, contractor scheduling and permits may lengthen as more buildings rush to modernize.

• Implementation logistics: downtime, coordination with tenants, contingency planning — especially critical in high-rise, high-traffic properties.

  
  

4. Modernization as an Opportunity

Rather than simply viewing this as a mandated fix, consider leveraging it as part of a broader modernization strategy: updating the controller, drive, ropes, cab design, energy efficiency, smart controls — and using the UCM upgrade (e.g., with the HydraSafe Brake system) as the safety differentiator for the building asset.

How HydraSafe Brake Fits In

With the evolving code requirement for unintended car motion protection, a solution like HydraSafe Brake becomes an ideal component of your modernization plan:

• Engineered to meet the safety demands of new UCM-code requirements.

• Compatible with retrofit or full modernization scopes — so you don’t just meet minimum code, you future-proof your system.

• Allows you to market your elevator systems (and building) as having “next-generation safety and modernization” rather than third-party tag of “just meeting code”.

  
  

Your Next Steps

1. Schedule an audit of your vertical transport assets: Which elevators are affected? What equipment do they currently have? What brake type?

2. Engage an elevator consultant or qualified contractor to review compliance with UCM requirements and advise on appropriate path (dual-plunger vs UCM device).

3. Include this upgrade in your capital modernization plan (not just a spot-repair), especially if your building is considering elevator machine/drive/rope upgrades.

4. Begin scheduling and budgeting early: factor in equipment lead times, permit processing, building tenant coordination, potential downtime.

5. Update your stakeholders (property managers, owners, tenants, board) with the narrative: “We are not just complying with the new code — we are upgrading our asset for safety, reliability, and value.”

6. Consider using HydraSafe Brake (or similar modern solution) and communicate that as part of your modernization story.

Final Word

The regulatory landscape around elevator safety is evolving — protection against unintended car motion is becoming a must-have, not just a “nice-to-have”. For building owners, managers, and elevator contractors, this presents both a compliance imperative and a modernization opportunity. If your traction elevators rely on single-plunger brakes or lack dedicated UCM protection, now is the time to act — and to leverage the upgrade as a value-add. With the right planning, investment and vendor solution (such as HydraSafe Brake), you can turn this requirement into a strategic upgrade rather than a last-minute fix.