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.
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.
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.
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.
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.
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
| Method | Easy | Medium | Hard | Extreme | All |
|---|---|---|---|---|---|
| UniAD | 0.367 | 0.198 | 0.249 | 0.109 | 0.224 |
| VAD | 0.400 | 0.228 | 0.242 | 0.095 | 0.239 |
| LTF | 0.634 | 0.391 | 0.289 | 0.098 | 0.360 |
| ECO (Smoothing-only) | 0.764 | 0.416 | 0.405 | 0.255 | 0.452 |
| ECO (Smoothing + Re-time) | 0.720 | 0.388 | 0.342 | 0.236 | 0.415 |
| Self-play teacher (ref., privileged state) | 0.780 | 0.497 | 0.639 | 0.185 | 0.520 |
| TerraTransfer (Ours) | 0.769 | 0.501 | 0.560 | 0.150 | 0.490 |
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.
Human-Like Simulation Agents via Self-Play Anchoring ICLR 2026
SPACeR anchors TerraZero's self-play RL to a pretrained tokenized reference model, making sim agents that are simultaneously human-like and reactive. The resulting policy is ~50× smaller than tokenized baselines with 10× faster inference, and outperforms prior self-play and imitation methods on the Waymo Sim Agents Challenge.
PPO
HR-PPO
SPACeR
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}
}