Lec 5. Ch.3P1 UT and TP system characteristics Relationship between Transportation trips and facilities/services System hierarchy and transportation facility classification System purpose System boundary for analysis System components (niches for different modes) System performance System capacity Ch. 3 Part 1 (3.1): Topics
Transportation trips Transportation is a trip from an origin to a destination taken primarily to accomplish some purpose. Facilities Services Modes
Transportation system? A system is a group of interdependent and interrelated components that form a complex and unified whole intended to serve some purpose through the performance of its interacting parts.
System hierarchy Functionally, the transportation system is just one of many systems that allow urban areas to exist. How does the transportation system interrelate with the other systems to provide livable communities? What is the cause and effect of relative investment in transportation as compared to other infrastructure systems as it relates to community development? What are the demands placed on transportation systems by changes in the urban system?
System purpose: two perspectives Transportation function itself: “Enabler” of other system activities as well as an important cause of negative impacts: Mobility: The ability and knowledge to travel from one location to another in a reasonable amount of time and for acceptable costs. Accessibility: The means by which an individual can accomplish some economic or social activity through access to that activity. e.g., transportation enables economic activity to occur or community interaction to happen, while at the same time, it could be a major source of air pollutants Tanjungkarang Telukbetung 600 km highway project Slamat sian! (Examine Portland’s TP system purposes.)
System boundary: it must be set before analysis begins! System boundary for a GA-based land use & transportation system optimization by Balling, Saito, et al. Example case The boundaries of the system being analyzed must be set first. The level of technical analysis within the system boundary is much more detailed than that associated with the area outside.
5 system components System users Stakeholders Transportation modes Infrastructure (facilities & services) Intermodal connections Intermodal connections are emphasized by ISTEA/TEA-21. Niches of modes
System performance & capacity System performance and capacity are related. Performance is often evaluated in relation to system capacity. Level of service: a measure that describes performance conditions in terms of operational characteristics of interest to users. A broader definition of system performance should also reflect the impressions and concerns of the customer or user of the system. Stable flow Unstable flow Density Flow SF A SF E A B C D E F Capacity
Planning applications of system performance and capacity System PerformanceSystem Capacity Reflect the vision that guides the planning process – e.g. Urban arterials designed for LOS = D as the worst case Act as a means of monitoring system changes over time – e.g. The arterial designed for D now experiences LOS = E most of the peak periods (slow, stop & go), and delay excessive Influence the type and scope of planning data and analysis tools – e.g. Use of reversible lane, TWLTL, bus lane, LT prohibition, signal coordination? Type of corrective options determine data and analysis types Building system capacity is one of the major items of FHWA (not necessarily by building new highways, but managing existing facilities better) – e.g. HOV, LRT, Pooling, reversible/contra-flow lanes The capacity of individual facilities or services can be affected by a variety of factors – e.g. Think how many factors affect capacity of signalized intersection Network and system capacity is directly related to the capacity of the “weakest” link in the network – that is, a bottleneck! Those intersections near Olive Garden at the Plum Tree Plaza
System control SLC SL Co WFRC Div. Of Public Safety Planned, designed, built, operated, and maintained by organizations and individuals with different objectives, mandates, constituencies, and problem definitions – e.g. Recall Mr. Hales presentation; see the diagram to the left Increasingly, private sector groups and organizations are playing a major role in providing transportation services and funding – e.g. public-private partnership in providing better mobility and access, like the developer shares the cost of improvements of intersections affected by the traffic from the development; a toll road maintained by a private organization
System feedback: two feedback mechanisms The feedback loop that relates the implementation of transportation strategies to their impact on community vision, goals/objectives, and on the operational characteristics of the system itself The market, that is the general interaction between the demand for transportation services and the supply of these services Transportation users (the consumers of transportation facilities and services) seek the least cost options if given choices. Captive users have less options
Dr. Saito’s travel mode choice logic: economic and community concern Commuting: Commuting by UTA is more economical (comparison without the Ecopass program) Shopping/recreation: Using his car is more economical His house is located 2 miles from the Y campus. Bus stops of the route serving BYU are ½ to 1 block away from his house. Buses come every 30 min. (considered convenient even for an Asian man’s standard, who did not own a car in his country and used public transit exclusively) The monthly pass is now $40. Since he rides 20 days/mo for commute, his expense for bus is $2.00/day. The Y stop is close to CB. Can read during commute. Bus commuting time is 100% HIS. It takes about min door-to-door. If he drives, 4 miles x 50 cents/mile (true cost of operating a vehicle) = $2.00/day. Parking is away from CB unless he comes very early! A bit stressful. Less use of his car prolongs his car’s service life. It takes about 15 min d-t-d. Multiple destinations in a shopping/recreation tour is done more economically (time-wise) by his car. Ever since he saw the Provo/Orem area covered by a thick smog (see it from Saratoga Spring if you want to check), he tries to do his best to reduce his auto trips.