Though there is a consensus that transport plays a central role in economic development, for the period before the eighteenth century there is a lack of strategic information for assessing the importance of road transport productivity changes in economic development. Transport prices in particular are crucial missing pieces of the puzzle. Sources rarely reveal information that meets the standards of reliable price history. However, it is possible to create a reliable transport price series on the basis of the transport of millstones to ducal mills in Brabant. Assessing the impact of the ‘transport productivity changes’ that can be inferred from this transport price series is a hazardous exercise. Moreover, as Masschaele has observed, land transport prices closely match general agricultural price trends. Land transport was essentially an agricultural service, determined both by cost (especially horse provender) and income effects. Transport price inflation was not demand‐led. However, while transport did not impede urbanization and economic growth, conversely, in sixteenth‐century Brabant—a highly urbanized region that experienced considerable growth in the volume of land transport—no significant land transport productivity gains were achieved.