Traffic Management

This report presents the definitions and calculations of five new network performance indicators. These indicators are measured on-line with the use of freeway and arterial traffic control systems. These systems provide 24-hour 7-day traffic data at a time resolution as small as 1 or 2 min and a spatial resolution of 0.3 1 km per detection device (the link length). The five new network indicators recommended for implementation are; Traveller Efficiency (Travel Speed), Traveller Efficiency (Variation from Posted Speeds), Traveller Efficiency (Arterial Intersection Performance), Reliability (Travel Speed), Productivity (Speed and Flow). The methods for their calculation closely follow those already used in the current NPI Program. It is the use of traffic control systems for the measurement of the five new NPIs that is innovative. All histograms use the same format and each presents the proportions of a network that operate in different ranges or bins of a performance indicator.