Traffic Congestion and Networks
https://ops.fhwa.dot.gov/congestion_report_04/chapter4.htm
Traffic congestion in urban areas is a constant issue. It can decrease population morale, pose safety risks by blocking emergency services and causing accidents and it has a severe negative effect on the environment by elevating greenhouse emissions. This page analyses the effects of various techniques to decrease congestion including metering freeways, creating additional thruways and better coordinating traffic signals. The combination of these elements greatly resembles the work we have done with directed graphs for our network traffic problems.
Beginning with a base delay in travel of 3600 million hours across 75 urban areas, the Texas Transportation Institute found that using a mixture of the strategies above would allow for more efficient travel. A graph of the cities can be thought of as two nodes, A and B that start and end the graph. Between these two are numerous other nodes with weights that describe the time of travel between them in terms of the total number of people along that path. Throughout the day and at different times of the year, the number of travelers varies. Since additional roads can’t be constructed at a moment’s notice, the use of metering may decrease the travel speed on certain edges, to gain a net increase in speed along other paths. With this, TTI concluded that an overall decrease in 500 million delay hours could be achieved. Here we see the concepts of network traffic and NE directly applicable in the infrastructure of our everyday life.