To provide a travel route calculation system capable of preventing deterioration of work efficiency by accumulating grains in a grain tank of a combine-harvester as much as possible while avoiding filling up the grain tank in the middle of traveling line.SOLUTION: A travel route calculation system comprises: a reaping and traveling route calculation unit which calculates a reaping and traveling route that is a traveling route for reaping and traveling in a farm field； an accumulation prediction unit which predicts whether a grain accumulation amount reaches a prescribed threshold value in the middle of a next traveling line LNb that is a traveling line LN planned to travel next time on the basis of detection result by an accumulation amount sensor in which the reaping and traveling routes consists of a plurality of traveling lines LN. The reaping and traveling route calculation unit performs, when the accumulation prediction unit predicts that the grain accumulation amount reaches the threshold value in the middle of the next traveling line LNb, a traveling line correction processing to correct the next traveling line LNb so that the grain accumulation amount does not reach the threshold value in the middle of the next traveling line LNb.SELECTED DRAWING: Figure 7【課題】走行ラインの途中でコンバインの穀粒タンクが満杯となることを回避しつつ、穀粒タンク内に可能な限り多くの穀粒を貯留させて作業効率の低下を防ぎやすい走行経路算出システムを提供する。【解決手段】圃場における刈取走行のための走行経路である刈取走行経路を算出する刈取走行経路算出部を備え、刈取走行経路は、複数の走行ラインＬＮにより構成されており、貯留量センサによる検知結果に基づいて、次に走行する予定の走行ラインＬＮである次走行ラインＬＮｂの途中で穀粒貯留量が所定の閾値に達するか否かを予測する貯留予測部を備え、刈取走行経路算出部は、貯留予測部により次走行ラインＬＮｂの途中で穀粒貯留量が閾値に達すると予測された場合に、次走行ラインＬＮｂの途中で穀粒貯留量が閾値に達しないように、次走行ラインＬＮｂを修正する走行ライン修正処理を行う。【選択図】図７
