StyleVLA: Driving Style-Aware Vision Language Action Model for Autonomous Driving
Authors: Yuan Gao, Dengyuan Hua, Mattia Piccinini, Finn Rasmus Schäfer, Korbinian Moller, Lin Li, Johannes Betz
Organizations: Y. Gao, D. Hua, M. Piccinini, F. Schäfer, K. Moller, J. Betz are with the Professorship of Autonomous Vehicle Systems, TUM School of Engineering and Design, Technical University of Munich, 85748 Garching, Germany; Munich Institute of Robotics and Machine Intelligence (MIRMI) · L. Li is with the School of Mechanical and Aerospace Engineering, Nanyang Technological University
Vision Language Models (VLMs) bridge visual perception and linguistic reasoning. In Autonomous Driving (AD), this synergy has enabled Vision Language Action (VLA) models, which translate high-level multimodal understanding into driving behaviors, typically represented as future trajectories. However, existing VLA models mainly generate generic collision-free trajectories. Beyond collision avoidance, adapting to diverse driving styles (e.g., sporty, comfortable) is essential for personalized driving. Moreover, many methods treat trajectory generation as naive token prediction, which can produce kinematically infeasible actions. To address these limitations, we present StyleVLA, a physics-informed VLA framework for generating diverse and physically plausible driving behaviors. We introduce a hybrid loss that combines a kinematic consistency constraint with a continuous regression head to improve trajectory feasibility. To train StyleVLA, built on Qwen3-VL-4B, we construct a large-scale instruction dataset with over 1.2k scenarios, 76k Bird's Eye View (BEV) samples, and 42k First Person View (FPV) samples, with ground-truth trajectories for five driving styles and natural-language instructions. Experiments show that our 4B-parameter StyleVLA significantly outperforms proprietary models (e.g., Gemini-3-Pro) and state-of-the-art VLA models. Using a composite driving score measuring success rate, physical feasibility, and style adherence, StyleVLA achieves 0.55 on BEV and 0.51 on FPV, versus 0.32 and 0.35 for Gemini-3-Pro. These results show that a specialized, physics-informed, lightweight model can surpass closed-source models on domain-specific tasks.
Figures & tables
Fig. 1: Concept of StyleVLA: Enabling driving style-aware trajectory generation via VLA model. Our framework yields diverse driving styles (Default, Balanced, Comfort, Sporty, Safety) in response to user instructions.
Fig. 2: Overview of the StyleVLA framework. Top (Dataset Construction): A motion planner generates style-specific ground-truth trajectories to create multimodal instruction samples. Instruction Dataset Generation: Details the instruction generation process and 3D scenario replay in CARLA. Bottom (Fine-tuning Architecture): The model predicts trajectory tokens using only an LLM head conditioned on visual context and language prompts. During training, an auxiliary MLP decoder maps the predicted tokens to continuous kinematic trajectories for physics-informed supervision. Training uses a physics-informed hybrid loss ( Ltotal ) combining cross-entropy ( Lce ), regression ( Lreg ), and kinematic consistency ( Lpikc ). Trajectory Generation: Shows the model’s application in both 2D BEV and 3D FPV domains.
Cost Term
Comfort
Balanced
Sporty
Safety
Default
Kinematic Constraints ( wkin )
Longitudinal Jerk ( wj,lon )
0.80
0.50
0.25
0.40
0.20
Lateral Jerk ( wj,lat )
0.80
0.50
0.25
0.40
0.20
Velocity Offset ( wv )
0.30
0.60
1.00
0.30
1.00
Distance to obstacles ( wobs )
0.30
0.80
0.60
2.00
0.00
External Perception ( wext )
TABLE I: Weights across Driving Styles, for the cost function ( 2 ) of the Frentix motion planner used for dataset generation.
Style Label
Samples
Avg Velocity
RMS Accel
RMS Jerk
Path Length
(Count / %)
( m/s )
( m/s2 )
( m/s3 )
( m )
Balanced
14,102 (18.5%)
7.15
0.588
0.750
24.44
Comfort
13,766 (18.1%)
7.21
0.585
0.727
24.53
Default
17,684 (23.3%)
6.80
0.486
0.794
23.31
Sporty
14,790 (19.5%)
7.32
0.558
0.780
25.13
Safety
15,688 (20.6%)
6.39
0.583
0.746
21.44
TABLE II: Mean Kinematic Features and Distribution of Filtered Trajectories by Style
Fig. 3: Example training dynamics of StyleVLA fine-tuning on the FPV instruction dataset. Top: loss terms ( Ltotal , Lce , Lreg , Lpikc ). Bottom: learned log-variance parameters ( wce , wreg ) that yield adaptive precision weights via exp(−w) .
Group
Value
Regression Loss Weights
(wreg,wpikc)
(2.0,2.0,0.5,0.5,0.5,1.5)
Training Hyperparameters ( FPV )
Backbone
Qwen3-VL-4B-Instruct
Quantization
QLoRA, 4-bit
LoRA (r,α,dropout)
(256,512,0.05)
TABLE III: Hyperparameters used in fine-tuning
Fig. 4: Qualitative comparison of style-conditioned trajectory generation under five driving styles (Default, Balanced, Comfort, Sporty, Safety). We visualize the goal, ground truth, and predicted trajectories from pretrained VLMs and SOTA baselines (see legend). ”*” failed to generate trajectories.
Configuration
ADE (m) ↓
FDE (m) ↓
PSR ↑
Heading MAE (rad) ↓
Impact of Training Data Scaling (with Physics-Informed Hybrid Loss)
Small (4.5k)
2.08
5.43
20.60%
0.073
Medium (20k)
1.51
3.92
27.14%
0.046
Large (40k)
1.47
3.81
29.37%
0.044
Standard (50k)
1.17
3.06
33.19%
0.035
Impact of Loss Components (50k Training dataset)
TABLE IV: Ablation on BEV StyleVLA (Qwen2.5-VL-7B, 3 s horizon). Scaling data and adding physics-informed hybrid loss consistently improves generalization
Model
Score ↑
PSR ↑
MR ↓
ADE ↓
FDE ↓
KCE ↓
Time ↓
(0-1)
(ADE <1 m)
(FDE >2 m)
(m)
(m)
(m)
(s)
Open Source Models
Qwen3-VL-4B
0.00
0.00%
100.0%
-
-
-
2.00
Qwen2.5-VL-7B
0.00
0.00%
100.0%
-
-
-
3.43
InternVL3-9B
0.00
0.00%
100.0%
12.63
25.89
3.72
5.77
Proprietary Models
TABLE V: Benchmarking across VLMs on BEV domain (Zero-Shot)
Model
Score ↑
PSR ↑
MR ↓
ADE ↓
FDE ↓
KCE ↓
Time ↓
(0-1)
(ADE <1 m)
(FDE >2 m)
(m)
(m)
(m)
(s)
Open Source Baselines
Qwen3-VL-4B (Base)
0.00
-
-
-
-
-
4.97
Proprietary Models
Gemini 2.5 Flash
0.12
9.04%
87.21%
9.39
18.21
3.42
1.80
Gemini 2.5 Pro
0.29
16.63%
70.74%
2.23
5.76
0.06
35.48
TABLE VI: Benchmarking across VLMs on FPV domain (Zero-Shot)
School of Electronic Information Engineering, Beihang University · Institute for AI Industry Research (AIR), Tsinghua University · National College for Excellent Engineers, Beihang University +5