Smartphone usage while driving is recognized as a compromise on road safety. We investigated if silencing and hiding of notifications from drivers (soft blocking) can reduce clicks on the screen while driving and if the effect of the soft blocking would be different for different speed thresholds (STs) (i.e., at driving speed greater than 0 km/h, greater than 1 km/h….and greater than 90 km/h). Drivers installed a smartphone application, which continuously monitored their phones. In the intervention group (N = 22), the application switched to the soft blocking mode during the study's intervention period, while in the control group (N = 29) it remained in a recording-only mode. We ran a Poisson regression model on the click events frequency (CEF) to estimate the soft blocking effect for each of the STs between 0 and 90 km/h. Our analyses indicated that the soft blocking effectiveness was indeed speed-dependent and pointed to a decline in CEF from ST > 55 km/h and to mixed results if ST < 55 km/h. We identify a potential of soft blocking to reduce phone usage while driving and recommend ST-dependent soft blocking. We also recommend using different STs in future investigations on the effectiveness of soft blocking.

驾驶时使用智能手机被认为是对道路安全的一种妥协。我们调查了静音和隐藏来自司机的通知（软阻塞）是否可以减少驾驶时在屏幕上的点击，以及软阻塞的效果对于不同的速度阈值 (ST) 是否会有所不同（即，在行驶速度大于 0 公里的情况下） /h，大于 1 公里/小时……并且大于 90 公里/小时）。司机安装了一个智能手机应用程序，可以持续监控他们的手机。在干预组 (N = 22) 中，应用程序在研究干预期间切换到软阻塞模式，而在对照组 (N = 29) 中，它保持在仅记录模式。我们对点击事件频率 (CEF) 运行泊松回归模型，以估计 0 到 90 公里/小时之间每个 ST 的软阻塞效应。我们的分析表明，软阻塞的有效性确实与速度有关，并指出 CEF 从 ST > 55 km/h 下降，如果 ST < 55 km/h，则结果好坏参半。我们确定了软阻塞的潜力，以减少驾驶时的电话使用，并推荐依赖于 ST 的软阻塞。我们还建议在未来对软阻塞有效性的调查中使用不同的 ST。