Xie Lian, Li Guangluo, Wu Chaozhong, Lyu Nengchao
School of Civil Engineering, Hunan City University, Yiyang, Hunan, China.
Guangxi Key Laboratory of Intelligent Transportation, Guilin University of Electronic Technology, Guilin, Guangxi, China.
Traffic Inj Prev. 2025;26(5):515-523. doi: 10.1080/15389588.2024.2436145. Epub 2024 Dec 12.
Exit ramps are accident-prone areas of freeways. One of the reasons for this is the information overload induced by destination signs, which makes them challenging to recognize and may even result in tension or mistakes. This study examined the cognitive workload that destination signs place on drivers and the compensatory behavior they use to counteract the additional workload.
Forty-five subjects were recruited to conduct a simulated driving experiment. Four destination signs with varying information levels were used to load mental workload as independent variables. Workload indicators (such as the NASA-TLX questionnaire, heart rate variability and eye movements) and compensatory behavior metrics (such as speed, distance headway, time headway and the increased cognitive time due to deceleration) were collected and analyzed through a mixed design analysis of variance.
The results show that destination signs with different levels of information produced various cognitive workloads. Drivers' subjective workload increased significantly with an increase in sign information; however, the heart rate variability indicators did not significantly differ due to the drivers' compensatory strategy in the cognition process. The principal compensating strategy found was the longitudinal deceleration; as the speed dropped, the distance headway and time headway were significantly increased. Although professional drivers demonstrated a significantly greater speed differential during deceleration than nonprofessional drivers, the alternative safety indicators did not show statistical differences. Additionally, driving experience had no significant impact on the increased cognitive time of compensatory strategies.
On the one hand, the effort invested by drivers increased with the workload. On the other hand, when the workload exceeded a particular degree, compensatory driving behavior was triggered, which in turn reduced the workload. There was no discernible difference in the effectiveness of the compensatory strategies employed by professional drivers and nonprofessional drivers under complex destination signs. The findings could provide safety considerations for the design of traffic signs.
高速公路出口匝道是事故多发区域。原因之一是目的地标志导致的信息过载，这使得它们难以辨认，甚至可能导致紧张或失误。本研究考察了目的地标志给驾驶员带来的认知负荷以及他们用来抵消额外负荷的代偿行为。
招募45名受试者进行模拟驾驶实验。使用四个信息水平不同的目的地标志作为自变量来加载心理负荷。通过混合设计方差分析收集并分析负荷指标（如NASA - TLX问卷、心率变异性和眼动）和代偿行为指标（如速度、车头间距、时间车头间距以及因减速导致的认知时间增加）。
结果表明，不同信息水平的目的地标志产生了不同的认知负荷。驾驶员的主观负荷随着标志信息的增加而显著增加；然而，由于驾驶员在认知过程中的代偿策略，心率变异性指标没有显著差异。发现的主要代偿策略是纵向减速；随着速度下降，车头间距和时间车头间距显著增加。尽管职业驾驶员在减速过程中的速度差异比非职业驾驶员显著更大，但其他安全指标没有显示出统计学差异。此外，驾驶经验对代偿策略的认知时间增加没有显著影响。
一方面，驾驶员投入的努力随着负荷增加。另一方面，当负荷超过特定程度时，会触发代偿驾驶行为，这反过来又降低了负荷。在复杂的目的地标志下，职业驾驶员和非职业驾驶员采用的代偿策略的有效性没有明显差异。这些发现可为交通标志的设计提供安全考量。
