The introduction of automated vehicles has redefined the level of interaction between the driver and the vehicle, introducing new tasks and so impose different workloads. Existing tools such as NASA-TLX and DALI are still used to assess driving workload in automated vehicles, despite not accounting for new tasks. This study introduces AV-TLX, a specialized tool for measuring workload in Level 3 automated driving. The development process began with a narrative literature review to identify the primary factors influencing workload. This was followed by a series of qualitative sessions during which the dimensions and later the questions of the questionnaire were designed. The tools validity was first assessed using CVR and CVI indices, and its reliability and convergent validity were evaluated using a dynamic driving simulator with high fidelity. The final version of AV-TLX comprises 19 questions across 8 subscales, demonstrating excellent reliability (0.86) and validity (CVR > 0.78). An agreement scores between the results of AV-TLX and NASA-TLX in the simulation study was 0.6, which is considered acceptable for the consistency of two questionnaires. Furthermore, this questionnaire can be utilized in two ways. First by reporting the overall workload and/or divided into 8 primary subscales, or by categorizing the questions into two groups including takeover task workload and automated driving task workload. The final version of this questionnaire, as presented in the paper, is available for use in future studies focusing on Level 3 automated driving.

翻译：自动驾驶车辆的引入重新定义了驾驶员与车辆之间的交互水平，带来了新的任务并因此施加了不同的工作负荷。尽管未考虑新任务，现有工具如NASA-TLX和DALI仍被用于评估自动驾驶车辆中的驾驶工作负荷。本研究介绍了AV-TLX，一种专门用于测量第3级自动驾驶工作负荷的工具。开发过程始于通过叙述性文献综述确定影响工作负荷的主要因素，随后进行了一系列定性讨论环节，以设计问卷的维度和后续问题。该工具的有效性首先通过CVR和CVI指数进行评估，其可靠性和收敛效度则使用高保真动态驾驶模拟器进行验证。AV-TLX的最终版本包含8个子量表的19个问题，展现出优异的可靠性（0.86）和有效性（CVR > 0.78）。在模拟研究中，AV-TLX与NASA-TLX结果的一致性评分为0.6，这被认为对于两份问卷的一致性是可接受的。此外，该问卷可通过两种方式使用：一是报告总体工作负荷和/或分为8个主要子量表，二是将问题分为接管任务工作负荷和自动驾驶任务工作负荷两组。本文提出的问卷最终版本可供未来专注于第3级自动驾驶的研究使用。