Thesis Essay Example
Travel Time Reliability Estimation using GPS and GIS
Basically, the research topic analysis requires the longitudinal and continual data through log normal distribution computing so as to realize the main objectives of the thesis. Transport time reliability estimation by using GPS and GIS tend to provide valuable measures to the transportation planners and the operators. The GPS data is easily attained through synthetically generating trips approach whereby it provides the calculation for travel time and reliability within the sourced data (Racca, p. 14). For effective data, it is recommended to use the high frequency GPS data that sends more accurate data like the travel time per section of the road (Hadachi, p. 33) Additionally, the use of GPS data gives an estimation of the roads hence easier to compute the travel time reliability estimation. The data can easily be collected by state fleet vehicles that have been equipped with GPS and drive across the country hence easier to gather data. It is also important to consider traffic congestion, positioned speed expected and the type of lanes such as HOT lanes.
To attain travel time reliability estimation, the computing process needs to involve the map matching technique, data reductions through transforming a series of locations, data proposing by engaging state fleet vehicles and data reporting (Uno, p 2-15). The process involves the use of tools such as java programming, SPPS statistical software, ARC workstations (ESRI) and the ARCGIS desktop inclusive of the excel spreadsheets. Both the programming process and basic procedures from above process ensures limited chances of GPS and GIS errors based on positional accuracy to estimate the time travel reliability.
Based on data collected from GIS and GPS, estimations of travel time reliability will be conducted in various approaches. The first approach is to use the buffer index. Buffer index is the most essential approach because most travelers tend to plan for a trip based on time issues. Buffer index entails an additional time added to the expected travel duration purposefully to the travel time reliability. As such, a computation is done on the differences of the 90th or 95th percentile of the travel time on the route and the average travel duration divided by the travel duration. For effective estimations, 95th percent is highly preferred for high reliability because it gives a worst scenario and the difference between it and the mean additional extra time position the travelers not to be late 95percent of the time. Its estimation is presented in the equation below
Buffer Index= 95th percent travel duration — Average travel duration x100%
Average travel duration
Developing GIS is much more beneficial to the research. The system strongly helps in tackling the map-matching problems of the targeted area. Additionally, the GIS offers greater advantage in managing the obtained data through GPS effectively. Through data reporting in estimations, GIS offers the best solutions. As such, developing the GPS-GIS system has a significant role in travel time reliability estimations that might solve challenges mainly on travel time issues and road congestions.
Hadachi, Amnir. Travel Time Estimation Using Sparsely Sampled Probe GPS Data in Urban Road Networks Contexts. 2013. Journal of Computer Science, Information Processing and System Laboratory.
Racca, David. Study and Calculation of Travel Time Reliability Measures. 2013. Center for Applied Demography & Survey Research, Delaware.
Uno, Nobuhiro. Using Bus Probe Data for Analysis of Travel Time Variability. 2014. Journal of Intelligent Transportation Systems, vol. 13, no. 1.
More Important Things