We focus on the U.S. Great Lakes megaregion, which includes large metropolitan areas such as Chicago, Detroit, Minnesota, Cleveland, St. Louis, and Pittsburgh. The dataset consists of a balanced panel based on the monthly data obtained from various sources. Variables measured in this study and the data sources are described in this section. We focus on the time period between 2013 July and 2016 May for data consistency.
Figure 1. US Great Lakes Megaregion (source: http://www.america2050.org)
3.2.1. Traffic Congestion Measure
Traditionally, two measures have been widely used for measuring traffic congestion. The first one is to use the average journey to work travel time, which is measured and provided by the U.S. Census Bureau. Average travel time is a simple way to measure overall levels of congestion, but it cannot provide specific commuter’s experience. For example, it only captures the average travel time during the certain time period, but it cannot consider traffic delay during the peak-period hours (rush hours) that are highly concerned by every commuters. The second one is to use travel delay index that can be …show more content…
Figure 3 describes the spatial and temporal distribution of traffic congestion growth in the Great Lakes megaregion. It shows that traffic congestion growth decreases with distance from the CBD like the geographical results shown in Figure 2. In addition, the second figure in Figure 2 shows that the range of the monthly PTI growth rate is between -4 and 6, but its average growth rate is almost 1.5 and constant during the period. This indicates that although the congestion growth rate is not stable, overall traffic congestion has increased in the US Great Lakes megaregion during the time
Figure 1. US Great Lakes Megaregion (source: http://www.america2050.org)
3.2.1. Traffic Congestion Measure
Traditionally, two measures have been widely used for measuring traffic congestion. The first one is to use the average journey to work travel time, which is measured and provided by the U.S. Census Bureau. Average travel time is a simple way to measure overall levels of congestion, but it cannot provide specific commuter’s experience. For example, it only captures the average travel time during the certain time period, but it cannot consider traffic delay during the peak-period hours (rush hours) that are highly concerned by every commuters. The second one is to use travel delay index that can be …show more content…
Figure 3 describes the spatial and temporal distribution of traffic congestion growth in the Great Lakes megaregion. It shows that traffic congestion growth decreases with distance from the CBD like the geographical results shown in Figure 2. In addition, the second figure in Figure 2 shows that the range of the monthly PTI growth rate is between -4 and 6, but its average growth rate is almost 1.5 and constant during the period. This indicates that although the congestion growth rate is not stable, overall traffic congestion has increased in the US Great Lakes megaregion during the time