Qhov luaj li cas ntawm rhuab phuam rail?

Qhov luaj li cas ntawm cov phuam da dej hluav taws xob feem ntau yog dab tsi, qhov kev teeb tsa qhov siab ntawm lub phuam hluav taws xob tuaj yeem txiav txim siab raws li qhov siab thiab qhov xwm txheej ntawm tus neeg. Yog tias muaj lub dab da dej, nws tuaj yeem ntsia tau rau ntawm qhov siab ntawm 1.8 meters los ntawm hauv av; yog tias nws tau muab cais tawm, nws tuaj yeem ntsia tau rau ntawm qhov siab ntawm 1.5 meters los ntawm hauv av. Cov txheej sab saud ntawm cov phuam da dej tuaj yeem dai cov phuam da dej, thiab cov txheej hauv qab tuaj yeem dai cov phuam da dej.