What caused the unexpected spike in disengagements during left turns at four-way intersections for Cruise this week?

Introduction

The unexpected spike in disengagements during left turns at four-way intersections for Cruise this week presents a critical issue for our autonomous vehicle technology. To address this problem, I'll employ a systematic approach to identify, validate, and resolve the root cause while considering both immediate and long-term implications for our product and users.

Step 1

Clarifying Questions (3 minutes)

• I'm noticing the specificity of the issue. Would you say this spike is isolated to left turns at four-way intersections, or are we seeing similar patterns in other scenarios?

Why it matters: This helps us determine if the issue is specific to left turns or indicative of a broader problem. Expected answer: The issue is primarily observed in left turns at four-way intersections. Impact on approach: If isolated, we'll focus on left turn algorithms; if widespread, we'll investigate system-wide changes.

• Considering the timing, I'm wondering about recent software updates. Have there been any significant changes to our perception or decision-making systems in the past week?

Why it matters: Recent updates could be directly related to the spike in disengagements. Expected answer: A minor update to the perception system was deployed last week. Impact on approach: If confirmed, we'll prioritize investigating the recent update and its potential unintended consequences.

• Looking at the data, I'm curious about the magnitude of the spike. Can you provide context on how much the disengagement rate has increased compared to our baseline?

Why it matters: Understanding the scale helps prioritize the issue and determine the urgency of our response. Expected answer: The disengagement rate has doubled from 1% to 2% for left turns at four-way intersections. Impact on approach: A significant increase would warrant immediate action, while a smaller spike might allow for a more measured response.

• Considering user safety, I'm thinking about any near-miss incidents. Have we received any reports of close calls or safety concerns from passengers or external observers?

Why it matters: Safety is paramount, and user feedback can provide valuable insights into the real-world impact of the issue. Expected answer: No serious safety incidents reported, but passengers have noted increased hesitation during left turns. Impact on approach: This would help us balance the urgency of the fix with the current safety implications.