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Transport agencies, such as the Queensland Department of Transport and Main Roads, routinely monitor roadway conditions and performance measures, and make necessary changes to enhance performance. These changes may be in response to road user complaints, staff observations of specific traffic problems, or systematic upgrades to traffic corridors. The impact of upgrades should be systematically evaluated to review the operational conditions of roadways/intersections. Though, evaluating the effects of upgrades, commonly performed with a before-after analysis, can be challenging due to (i) heterogeneous data sources,(ii) various performance measures, and (iii) underlying patterns in the data that could mask the real benefits (if any) of the changes.

This study proposes a systematic framework to quantify the effects of upgrades to road infrastructure, such as signal timing plans. Accurate travel time data is a key input in an upgrade evaluation process, and there are a variety of methods to collect this data, such as Global Positioning System (GPS) probe data and Bluetooth. Depending on the source of data, spatial and/or temporal aggregation may be required, which has an important impact on travel time statistics (Büchel and Corman, 2020). There are several studies comparing these data collection methods. For example, Berzina et al.(2013) performed a statistical analysis to evaluate three different data collection methods, while Zhang et al.(2015) proposed a scheme to validate arterial travel time based on GPS probe and Bluetooth data as two independent sources.