If you leave aside peak traffic times, holidays, nights, and the peach blossom season [when gravel trucks are banned from the highway], then during other times the rate of trucks going along the highway could be as high as one per minute, which is really too concentrated.
扣掉上下班尖峰、假日、夜間和水蜜桃旺季等時段，高峰時的車流量可達一分鐘一部，密度實在太高。