A driving scenario in the DriveHierarchy simulator, with the ego vehicle approaching an urban intersection.
NEURIPS 2026 / ACCEPTED

SEE THE CAPABILITY. UNDERSTAND THE DRIVE.

DriveHierarchy.

A Benchmark for Diagnosing VLM Driving Capabilities
from Open-Loop Understanding to Closed-Loop Execution

Chengkai Xu1Jiaqi Liu2Yicheng Guo1Peng Hang1Jian Sun1

1 Tongji University2 UNC Chapel Hill

DISCOVER THE BENCHMARK ↓OPEN-LOOP UNDERSTANDING → CLOSED-LOOP EXECUTION
01 / OVERVIEWBEYOND A SINGLE SCORE

What does it take
to understand the drive?

Driving intelligence is more than one ability. Its evaluation should be, too.

DriveHierarchy connects perceptual grounding, contextual memory, and mental reasoning to closed-loop driving. It reveals where VLMs succeed, where they struggle, and which capabilities offer targets for improvement.

4Capability ranks
76,798Full-corpus QA pairs
84,279Full-corpus frames
100Closed-loop scenarios
15VLMs evaluated

Paper evaluation: 14,000 open-loop records across 14 tasks, with 1,000 records per task. Full-corpus statistics are shown above.

Framework overview showing dataset construction, R1–R4 capability ranks, and diagnostic outputs.View full figure ↗
FIG. 01 A unified framework for capability diagnosis and benchmark-guided improvement.
Read the research abstract +

Evaluating VLM-based autonomous driving remains difficult because driving competence is composite: a capable system must ground traffic participants and hazards, integrate context across views and time, reason about future evolution, and act appropriately under closed-loop interaction. DriveHierarchy organizes these capabilities into four ranks. It integrates multiple open-source autonomous-driving datasets into a unified open-loop benchmark and provides a closed-loop simulation platform with interactive scenario construction on a real-world road network. Experiments on 15 VLMs reveal structured but non-redundant capability variation, connect open-loop understanding to closed-loop driving, and support targeted diagnosis and benchmark-guided optimization.

Condensed from the paper abstract.

02 / THE CAPABILITY HIERARCHYUNDERSTANDING → ACTION

Four ranks.
One connected picture.

Explore the abilities behind driving behavior.
Select a rank to see what it measures.

Front camera observation from the paper's open-loop examples.OPEN-LOOP / VISUAL OBSERVATION
R1 · 8 OPEN-LOOP TASKS

Ground the scene.

Recognize traffic participants and hazards, estimate distances, localize referred objects, and describe the current traffic situation.

  • Object existence, counting, and attributes
  • Nearest-object, referred-object, and bucketed distances
  • Visual grounding and situation description
Explore task records ↗
03 / INTERACTIVE SCENARIO EDITORNO PROGRAMMING REQUIRED

Your scenario.
Your design.

Turn a driving question into a custom scenario.
Visually configure actors, trajectories, and conditions without writing scenario scripts.

DriveHierarchy R4 platform diagram showing the interactive scenario editor, CARLA–SUMO co-simulation engine, performance evaluation, and replay analysis.View full platform ↗
From custom scenario design to closed-loop evaluation · R4 platform overview
01

Set the starting point

Initialize the ego vehicle's placement and state.

02

Shape the interaction

Place vehicles, pedestrians, and other dynamic actors around the ego vehicle.

03

Design the movement

Edit actor trajectories to create merging, yielding, and crossing interactions.

04

Change the conditions

Configure weather and refine the scene around your research question.

DESIGN→CARLA + SUMO→EVALUATE→REPLAY & ANALYZE

CARLA supplies rendering, vehicle physics, and sensor simulation.
SUMO coordinates background traffic. Logs and replay help you investigate failures.

Simulation setup ↗
INSIDE THE EDITOR

Design directly on the road network.

The actual visual interface for configuring your driving scenarios.

Screenshot of the visual scenario editor showing a road network and actor placement tools.Explore the interface ↗
Actual editor interface · from the paper
04 / SCENARIO EXPLORER100 SCENARIOS · 10 FAMILIES

A world of
driving interactions.

Built on a real-world road layout.
Curated to challenge interactive execution.

Simulation example of a pedestrian encounter.Enlarge scene ↗
01 / 10

Pedestrian encounters

Detect crossing intent, decelerate in time, yield when required, and resume only after the conflict region is clear.

R4 · SIMULATION
Explore the test-site scenario map +Scenario types distributed across the real-world road layout used in simulation.
05 / EXPERIMENTAL RESULTS15 OPEN-SOURCE VLMS

Different strengths.
Measurable differences.

Generalist and driving-specialized models,
evaluated across understanding and execution.

Paper results · sorted by open-loop score · higher is better
RankModelParametersOpen-loop score ↑Closed-loop score ↑

15 models · Tables 1 & 2 in the paper. The two scores use different evaluation protocols and should not be compared numerically across columns.

CAPABILITY PROFILES

A score tells you how much.
A profile shows you where.

Compare task-level strengths within a model family or across similarly sized models.

Figure labels R2-1-A/B/C correspond to repository tasks R2_1, R2_2_A, and R2_2_B. These profiles cover R1–R3.

Radar plot comparing open-loop capabilities of representative 8B–12B VLMs.View full figure ↗
06 / FROM DIAGNOSIS TO IMPROVEMENTBENCHMARK-GUIDED FINE-TUNING

Find the weakness.
Improve the drive.

Open-loop capability supervision can transfer to closed-loop behavior.

In a Qwen3-VL-8B-Instruct case study, jointly fine-tuning on the identified weak capability groups raises the average R4 score from 0.902 to 8.021. R4 was never a supervision target.

+7.119R4 score improvement
in the joint intervention

One base model, under the paper's protocol. Table 4 reports the closed-loop transfer study.

OPEN-LOOP ↔ CLOSED-LOOP

Related, yet not interchangeable.

Spearman correlations with R4 across the evaluated models.

0.664R1 ↔ R4
0.596R2 ↔ R4
0.418R3 ↔ R4
07 / BUILD ON DRIVEHIERARCHYRESOURCES & CITATION

Your next driving
research starts here.

Get started on GitHub ↗
BIBTEX
@inproceedings{xu2026drivehierarchy,
  title     = {{DriveHierarchy}: A Benchmark for Diagnosing {VLM} Driving
               Capabilities from Open-Loop Understanding to Closed-Loop Execution},
  author    = {Xu, Chengkai and Liu, Jiaqi and Guo, Yicheng and Hang, Peng and Sun, Jian},
  booktitle = {Advances in Neural Information Processing Systems},
  year      = {2026},
  url       = {https://github.com/PerfectXu88/DriveHierarchy}
}

Citation based on the accepted manuscript; final proceedings metadata can be added when available.