BREAKTHROUGHS IN ANALYTICAL TECHNIQUES

The first breakthrough in using an analytical technique for travel forecasting came in 1955 with the publication of a paper entitled "A General Theory of traffic Movement" by Alan M. Voorhees (1956). Voorhees advanced the gravity model as the means to link land use with urban traffic flows. Research had been proceeding for a number of years on a gravity theory for human interaction.
※traffic movement: 交通流（本来はtraffic flow）

BREAKTHROUGHS IN ANALYTICAL TECHNIQUES
分析技術の躍進

The first breakthrough in using an analytical technique for travel forecasting came in 1955 with the publication of a paper entitled "A General Theory of traffic Movement" by Alan M. Voorhees (1956).
①1955年、「交通流理論(A General Theory of traffic Movement)」(Alan M. Voorhees、1956)という論文の発表は，交通需要予測手法の最初の画期的な成果（ブレークスルー）であった。

Voorhees advanced the gravity model as the means to link land use with urban traffic flows.
②ボールヒーズ(ヴォールヒーズ)は、土地利用と都市交通流を連結させる手法として、重力モデルを進化させた。

Research had been proceeding for a number of years on a gravity theory for human interaction.
③人々の相互作用を把握するため、重力理論に関する研究は、長年の間、実施されていた。

Previously, the gravity analogy had been applied by sociologists and geographers to explain population movements. Voorhees used origin-destination survey data with driving time as the measure of spatial separation, and he estimated the exponents for a three-trip purpose gravity model. Others conducting similar studies soon corroborated these results (U.S. Dept. of Commerce, 1963a).

Previously, the gravity analogy had been applied by sociologists and geographers to explain population movements.
④以前は、重力類推法(アナロジー)は、人口移動の説明のため、社会学者や地理学者によって用いられた。

Voorhees used origin-destination survey data with driving time as the measure of spatial separation, and he estimated the exponents for a three-trip purpose gravity model.
⑤ボールヒーズは、運転時間を距離尺度とするOD(発着地)調査のデータを用いて、3つのトリップ目的の重力モデルの指数を推定した。

Others conducting similar studies soon corroborated these results (U.S. Dept. of Commerce, 1963a).
⑥同様な研究をしていたほかの研究者は、すぐにこれらの結果を確認した(U.S. Dept. of Commerce, 1963a)。