Cities 30 on Rennes Métropole

This layer indicates the municipalities of Rennes Métropole applying a speed limit of 30 km/h for at least one agglomerated area of its territory. In built-up areas, the speed of motor vehicles is one of the main factors involved in serious and fatal accident scenarios involving a pedestrian. On a regular basis, users who have to use the pavement for their traffic (pedestrians, people with disabilities) find themselves forced to use the pavement due to the absence of a pavement or the presence of a pavement that does not meet the regulatory requirements. This contributes to the increased risk for these users – in particular with the decrease in public lighting in the evening and at night. However, the reduction from 50 km/h to 30 km/h has been shown to significantly reduce the risk of pedestrian deaths. Speed is involved in several ways: severity of the impact and impact on the vulnerable user, and increased braking distance and distance travelled during the reaction time (half of motorised users hitting a pedestrian did not have time to start braking before impact). Switching to a maximum authorised speed of 30 km/h or less therefore makes it possible to improve the safety of pedestrians and persons with disabilities travelling on the road. Among the attributes: \- city_30: Boolean indicating by Yes/No whether the municipality has engaged in a City 30 approach; \- annee_ville_30: Year of passage to City 30 of the first agglomerated area of the municipality.本图层标注了雷恩都会区（Rennes Métropole）境内至少有一处集聚建成区实施30公里/小时限速的市镇。 在城镇建成区内，机动车行驶速度是引发行人重伤或死亡类交通事故的核心诱因之一。常态下，依靠人行道通行的交通参与者（行人、残疾人）常会因辖区未设置人行道，或现有人行道不符合合规标准，被迫在车行道上通行。这进一步推高了此类群体的出行风险，尤其在傍晚及夜间公共照明不足的场景中。 但现有研究表明，将机动车限速从50公里/小时降至30公里/小时，可显著降低行人死亡风险。车速对事故风险的影响体现在多个维度：一是碰撞烈度及对弱势交通参与者的伤害程度，二是制动距离与驾驶员反应时长内的车辆行驶距离——半数撞到行人的机动车驾驶员在碰撞发生前未及采取制动措施。因此，将最高法定限速调整为30公里/小时或更低，可有效提升道路上行人与残疾人的出行安全。 数据属性说明如下： - city_30：布尔型字段，以“是/否”标识该市镇是否采用了“30公里/小时限速城区（City 30）”模式； - annee_ville_30：该市镇首个集聚建成区实施30公里/小时限速城区模式的年份。