Applied Intuition · Technical Report

TerraTransfer: Learning End-to-End Driving Policies Without Expert Demonstrations

A demonstration-free recipe for end-to-end driving: learn to drive by self-play in a vectorized simulator, then align a vision policy to the frozen teacher — no expert supervision at any stage.

1 Applied Intuition  ·  2 UCLA  ·  3 UC Berkeley

The Idea

Decouple learning to drive
from learning to see

Master driving first by self-play in a fast vectorized simulator — then let the agent see, by aligning a vision frontend to the skills it already has.

0expert demonstrations, at any stage
≈2,535 yrsof self-play driving experience (8×1011 steps)
0.490HD-Score — beats every end-to-end baseline
Full abstract

End-to-end autonomous driving has achieved state-of-the-art performance on benchmarks and real-world deployments. Its standard training recipe, however, is expensive across all stages: collecting and labeling millions of driving frames is costly, and closed-loop RL on images is bottlenecked by the per-step cost of photorealistic rendering plus a forward pass through a large vision backbone. Self-play in vectorized simulators changes the economics: millions of rollout steps per second, and a state distribution naturally rich in collisions, near-misses, and recoveries that no driving log contains.

Our approach exploits this asymmetry by decoupling learning to drive from learning to see. We pretrain a single policy by self-play, then align its latent space with a pretrained vision backbone, through the action KL divergence and a batch-relational low-rank structural loss. The action target comes from the self-play policy, so alignment never supervises against a logged trajectory: a paired dataset of (image, scene-state) frames suffices, with no need for the curated expert demonstrations that imitation pretraining is built on. On photorealistic 3D Gaussian splatting closed-loop scenarios, the resulting end-to-end policy matches or exceeds prior end-to-end methods.

Method · Phase 1

Learn to drive — by self-play

One shared policy controls every agent in TerraZero, our vectorized simulator. Trained with PPO, it learns from the long tail of its own behavior — collisions, near-misses, recoveries — never imitating a human.

TerraZero · massively-parallel self-play8×10¹¹ steps
Ego encoderMLP Road encoderDeepSets Partner encoderDeepSets Shared MLPtrunk Action Headπ(a | state) PPO · actions fed back → interaction distribution co-evolves
8×1011simulated steps
≈23Mdriving hours
≈2,535 yrsof driving experience
0demonstrations

Method · Phase 2

Learn to see — align a vision student to the frozen teacher

The self-play policy is frozen and becomes the teacher. A DINOv3 encoder with a trained adapter maps camera images into the teacher’s feature space — supervised by a feature alignment loss and an action KL loss on paired (image, scene-state) frames. No logged trajectory is ever a target.

TrainableFrozen END-TO-END POLICY
Camera
DINOv3 + Adapterfrozen backbonetrained adapter Ego encoderinherited · frozen road + partner feat. ego features Action Headfrozen driving actions SELF-PLAY TEACHER · FROZEN
3D vector state
Ego encoderMLP · frozen Road encoderDeepSets · frozen Partner encoderDeepSets · frozen teacher features Action Headfrozen driving actions (state) Feature alignment lossrelational geometry · low-rank subspace Action match loss (KL)match action distribution

Results

Matches or beats every end-to-end baseline

Closed-loop HD-Score on HUGSim — 88 photorealistic 3D-Gaussian-splatting scenarios. Aligned on nuPlan, evaluated on nuScenes: the scores also reflect cross-dataset generalization.

UniAD0.224
VAD0.239
LTF0.360
ECO (best variant)0.452
TerraTransfer (ours)0.490
Self-play teacher (privileged state)0.520

Within 0.03 of its own privileged teacher — with no logged-trajectory supervision. The one exception is the strongly out-of-distribution Extreme tier, where our policy’s conservative responses preserve safety but sacrifice route completion.

Full per-tier table
MethodEasyMediumHardExtremeAll
UniAD0.3670.1980.2490.1090.224
VAD0.4000.2280.2420.0950.239
LTF0.6340.3910.2890.0980.360
ECO (Smoothing-only)0.7640.4160.4050.2550.452
ECO (Smoothing + Re-time)0.7200.3880.3420.2360.415
Self-play teacher (ref., privileged state)0.7800.4970.6390.1850.520
TerraTransfer (Ours)0.7690.5010.5600.1500.490
Closed-loop HD-Score on HUGSim (higher is better). Bold marks the best per column among comparison methods; the self-play teacher drives from privileged vectorized state and is excluded.

Qualitative Rollouts

Naturalistic driving across the long tail

Terra Series

Part of the Terra Series

Procedural Driving Simulation for Self-Play RL at Scale

TerraZero is the vectorized simulator and self-play recipe behind Phase 1 of TerraTransfer: a fast object-level traffic simulator, a procedural scenario generator, and a compute-efficient self-play recipe that trains driving policies from scratch — with zero human demonstrations — and transfers them across cities and datasets. Its frozen self-play planner is the teacher distilled into the end-to-end vision policy on this page.

BibTeX

Cite This Work

@article{xiong2026terratransfer,
  title   = {TerraTransfer: Learning End-to-End Driving Policies Without Expert Demonstrations},
  author  = {Xiong, Zikang and Li, Weixin and Wu, Zhouchonghao and Rangesh, Akshay
             and Bonde, Saarth and Hall, Grantland and Tang, Chen and Hu, Yihan and Zhan, Wei},
  journal = {arXiv preprint arXiv:2606.17386},
  year    = {2026}
}