Traffic congestion is one of the main problems in large urban cities. The evaluation of the performance of any traffic facility, such as basic freeway segments, merging sections and diverging sections, depends mainly on investigating the main relationships such as speed-flow and flow-occupancy. This study has focused on the fundamental relationships of traffic stream, including flow-speed, flow-density, speed-density (Greenshield relationships), headway-flow and flow-occupancy relationships. 24-hour data, each minute, from loop detectors has been adopted to produce the above mentioned relationships. Field data has been collected from two different sites in Manchester city in the UK. These are three-lane and four-lane sections. In some cases of the current data, the behaviour has been investigated under 1min, 5min and 15min periods to show the difference between various periods of data collection. The analysis of this data has revealed different behaviours at different sections for each lane. The main use of this data is to provide the critical values which are the basis for Intelligent Transportation System (ITS) applications, such as simulation models. This data could be used for the calibration and validation of simulation models, such as S-Paramics or VISSIM, as well as other developed models. [ABSTRACT FROM AUTHOR]