[1] Be careful on the road.[2] Watch out on the road.[3] Drive safe(ly).[4] Walk safe(ly).[5] Stay safe.[6] Be safe.[7] Safe travels. Travel safe(ly). Have a safe trip. Have a safe journey.[8] Be careful.[9] Take care.
Be careful on the road. Watch out on the road. Drive safe(ly). = 開車小心 Walk safe(ly). = 走路小心 Stay safe. = 注意安全 (別說 stay safely) Take care. = 最通用的說法，跟人分別時用這句話就表示路上小心、注意安全、或好好照顧自己
safe 也可以當副詞使用。
而以下的句子都能用在當對方要去旅行時或當跟對方道別(不管距離多遠)時，表明你希望他們路上小心:
Have a safe trip. Have a safe journey. Safe trip. Safe journey. Safe travels. Travel safe(ly).
This is a cain of problems. Burning oil leads to increase in carbon dioxide, which leads to the greenhouse effect, which leads to melting of glaciers, which leads to rising sea levels.
