Several past studies developed acceleration/deceleration rate models as a function of a single explanatory variable. Most of them were spot speed studies with speeds measured at specific locations on curves (usually midpoint of the curve) and tangents to determine acceleration and deceleration rates. Fewer studies adopted an estimated value of 0.85 m/s² for both deceleration and acceleration rates while approaching and departing curves, respectively. In this study, instrumented vehicles with a high-end GPS (global positioning system) device were used to collect the continuous speed profile data for two-lane rural highways. The speed profiles were used to locate the speeds at the beginning and end of deceleration/acceleration on the successive road geometric elements to calculate the deceleration/acceleration rate. The influence of different geometric design variables on the acceleration/deceleration rate was analysed to develop regression models. This study also inspeced the assumption of constant operating speed on the horizontal curve. The study results indicated that mean operating speeds measured at the point of curvature (PC) or point of tangency (PT), the midpoint of curve (MC), and the end of deceleration in curve were statistically different. Acceleration/deceleration rates as a function of different geometric variables improved the accuracy of models. This was evident from model validation and comparison with existing models in the literature. The results of this study highlight the significance of using continuous speed profile data to locate the beginning and end of deceleration/acceleration and considering different geometric variables to calibrate acceleration/deceleration rate models.

中文翻译：

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使用全球定位系统数据对两车道农村公路的加减速率进行建模

过去的几项研究根据单个解释变量开发了加速/减速率模型。其中大多数是点速度研究，使用在曲线上特定位置（通常是曲线的中点）和切线处测得的速度来确定加速度和减速度。较少的研究采用了0.85 m / s ²的估计值分别接近和离开曲线时的减速度和加速速度。在这项研究中，使用带有高端GPS（全球定位系统）设备的仪表车辆来收集两车道农村公路的连续速度曲线数据。速度曲线用于在连续道路几何元素上定位减速/加速开始和结束时的速度，以计​​算减速/加速率。分析了不同几何设计变量对加/减速率的影响，以建立回归模型。这项研究还检验了水平曲线上恒定运行速度的假设。研究结果表明，在曲率点（PC）或切点（PT），曲线中点（MC），并且曲线的减速结束在统计上是不同的。作为不同几何变量的函数的加速/减速率提高了模型的准确性。从模型验证和与文献中现有模型的比较中可以明显看出这一点。这项研究的结果突出了使用连续速度曲线数据定位减速/加速的开始和结束以及考虑不同的几何变量来校准加速/减速率模型的重要性。