An improved method of travel time estimation on a freeway with focusing on the freeway section charac‐teristics is proposed .In consideration of traffic flow fluctuation and influence areas on different sections ,the proposed method optimizes the estimates of the travel time on freeway sections based on the locations of ramps on the link and it is applicable for the freeway sections with ramps which cause an uneven traffic flow .The proposed method was tested on Nanjing Airport Highway as a case study by simulated speed from Vissim and the actual travel time .The results show that the accuracy of travel time estimates could increase 3 .71% and 4 .59% comparing to the estimates by semi‐distance method and space linear interpolation method respectively when the traffic flow rates of ramps were balanced ;the accura‐cy of travel time estimates could increase 16 .27% and 17 .29% respectively when the traffic flow rates on ramps were sig‐nificant different .The results confirmed that the proposed method could provide more accurate travel time estimates on freeways .
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