The HOV lane case
Most urban car trips register low occupancy rates, around 1.20 passengers per car. Originated in the US in the late 1960s, High Occupancy Vehicle (HOV) lanes aim to improve mobility by optimizing vehicle occupancy and thus bring on an improved traffic flow, more efficient fuel economy and better environment. Madrid benefits from a 10 year-old HOV lane that has enjoyed success in terms of its functional traffic flow parameters. Variable Message Signs indicate the HOV lane availability, although the essential information is displayed via text. The study tests the judged comprehensibility of several pictograms intended for the HOV lane referent.