1. Txhim kho guardrails, laum qhov ntawm phab ntsa, thiab qhov sib nrug yuav tsum tsis pub dhau 3 centimeters raws li qhov xav tau tiag tiag;
2. Siv cov kev ntsuas los tiv thaiv zoo li qub, xws li hauv av hauv qhov chaw ua haujlwm, hnav cov khaub ncaws tiv thaiv zoo li qub rau cov neeg ua haujlwm, thiab siv cov kev ntsuas tiv thaiv zoo li qub, vim qhov muaj peev xwm tiv thaiv zoo li qub ntawm LED dej nyab teeb ntawm qib sib txawv;
3. Ua tib zoo saib xyuas kev sib khi thaum lub sijhawm teeb tsa. Kev sib khi tsis zoo tuaj yeem ua rau lub neej ntev ntawm LED dej nyab vim txoj kab uas hla;
4. Txoj kab hluav taws xob ntawm LED dej nyab yuav tsum tsis pub tshaj 25 centimeters, thiab cov khoom siv hluav taws xob muaj zog tuaj yeem ua kom ntev ntev, txwv tsis pub nws yuav cuam tshuam qhov ci.