Lighting-Based Communication for Safe Auto Flush Door Handles

Automotive Lighting Interaction Visual Communication

Problem: Lack of communication between the vehicle door and the external environment leads to unintended door-opening and door-ding accidents.

Solution: Lighting-based visual communication provides real-time cues that make door interaction predictable, safe, and intuitive.

Project cover image

Background

" Vehicle door handles are one of the key touchpoints during entry and exit "

Non-Collision Accidents Related to Vehicle Doors

  • Approximately 647,000 non-collision accidents occur annually
  • Many of these accidents happen during entry and exit
  • ① Dooring (collisions with approaching vehicles or pedestrians)
  • ② Door-ding accidents in confined spaces
  • ③ Hand entrapment during handle retraction

Limitations in Door Interaction

  • Limited communication between the vehicle's internal state and its surroundings
  • ① Drivers and passengers → difficulty perceiving surrounding conditions
  • ② People outside the vehicle → difficulty predicting door movements

Fig. 1. Example of a dooring accident in a real-world scenario
(Source: Bobaedream user post)

User Research

" Lack of real-time information makes door interaction unpredictable, leading to unsafe, guesswork-based behavior "

Field Observation

  • Difficulty noticing approaching vehicles and pedestrians
  • Sudden door opening in traffic flow
  • Increased risk in low-visibility and confined environments

User Interviews

  • Safety concerns during entry and exit
  • Limited understanding of door behavior
  • Difficulty anticipating handle movement

Survey Results

  • Unnecessary movement due to unknown seat availability (84.8%)
  • Strong preference for having information before interaction

Problem

" Limited awareness and lack of communication during vehicle entry and exit lead to collision risks, hand entrapment, and door-ding accidents "

Goal

" To bridge the communication gap between the vehicle's interior and its surroundings through the door handle. "

Solution

Exit Notification

Communicates when passengers are getting in or out of the vehicle

  • Unlocking from inside → Exterior handle deploys
  • During exit interaction → Lighting blinks to provide feedback
Handle Deployment

Fig. 2. Handle Deployment

Lighting Feedback and Notification flowchart Lighting Feedback and Notification flowchart

Fig. 3. Lighting Feedback and Notification Flowchart

Seat Availability Guidance

Allows users to check seat availability before entering

  • Displays the number of available and occupied seats
  • Helps users decide whether to board without opening the door
Available and Unavailable Seat

Fig. 4. Available and Unavailable Seat

Narrow-Space Safety Lighting

Projects light onto the ground to indicate the door-opening range

  • Visualizes door swing area to prevent door-ding accidents
  • Warns nearby pedestrians and vehicles before the door opens
Spatial Safety Lighting Spatial Safety Lighting Spatial Safety Lighting

Fig. 5. Spatial Safety Lighting

Flush Handle Timing Visualization

Communicates handle retraction timing to prevent hand entrapment

  • Displays a countdown before the handle retracts
  • Warns users in advance to release the handle safely

Fig. 6. Handle Timing Visualization

User Scenario

① Pre-boarding Awareness

Pre-boarding Awareness

Identify vehicle status through lighting cues.

② Ergonomic Access

Ergonomic Access

Easily locate and grasp the handle, even in low light.

③ Seat Availability

Seat Availability

Check available seating before entering.

④ Collision Prevention

Collision Prevention

Signal door opening to nearby vehicles and pedestrians.

⑤ Door Movement Visualization

Door Movement Visualization

Understand door range to avoid collisions.

⑥ Real-time Feedback

Real-time Feedback

Receive warning before handle retraction to prevent hand entrapment.

Result

Process

Usability Evaluation

  • Participants: 60 users (ages 10–30)
  • Method: Prototype-based survey & interview
  • Objective: Evaluate effectiveness of lighting for indicating interior availability
  • Constraint: Limited use of color due to legal regulations
  • Test A: Amber lighting only → Information via ON / OFF state
  • Test B: Color lighting → Information via Green / Red

Fig. 7. Test A Experimental Prototype

Results

  • Test A: ~80% correctly interpreted lighting as "Available to enter"
  • Test B: ~90% correctly interpreted green lighting as availability

Interpretation

  • Lighting alone enables intuitive information delivery
  • Adding color improves recognition accuracy by ~10%
Interpretation

Fig. 8. Test B Experimental Prototype

" Achieved up to 90% accuracy, enabling safer and more predictable door interaction "