TP exam2 Flashcards
4 steps of the traditional four–step process of urban travel demand
Trip Generation, Trip Distribution, Mode Split, Traffic Assignment
Trip Generation (inputs, outputs, and models)
socioeconomic conditions and land use (in), productions/attractions (out) w/linear regression model
Trip Distribution (inputs, outputs, and models)
productions/attractions (in), trips (out) w/gravity model
Mode Split (inputs, outputs, and models)
trips (in), trips by mode (out) w/Logit Model
Traffic Assignment (inputs, outputs, and models)
trips by mode (in), travel time and level of service (out) w/user equilibrium or system optimal
There are two different types of modal split models identified in the text – what are they?
Trip–End Models & Trip–Interchange Models
Define the logit model including a mathematical representation of the model and definitions of each term.
traveler with a choice tends to choose the travel mode that has the greatest utility\nP = e / sigma e equation…
Trip–End Models, definition, (when should it be used, and why?)
based on assumption that ridership is due to socioeconomic variables “captive” users; use before trips distributed; used for small\ncommunities or in developing countries
Trip–Interchange Models, definition, (when should it be used, and why?)
Logit model, use after trip distribution, looks at multiple socioeconomic factors and trips to determine split
Trip assignment – Interaction between supply and demand ?
demand – output from first three steps of process, supply – network (roadway, transit routes) and costs (travel time, distance, tolls)
user equilibrium
based on the assumption that each individual chooses the route perceived as being the best
system optimal
users are assigned to routes so as to minimize the system wide average cost of travel, generally does not yield same result as user equilibrium
4 traffic assignment techniques outlined in Section 5.4.4 of Meyer & Miller’s text
minimum path (all–or–nothing), equilibrium assignment, stochastic assignment, dynamic assignment
minimum path (all–or–nothing)
all traffic between a given origin and\ndestination is loaded on the links comprising the minimum path and nothing is loaded on the other links
equilibrium assignment
volume on links change until travel time on links become the same
stochastic assignment
user equilibrium, based on the assumption that each individual chooses the route perceived as being the best (i.e., each individual\nminimizes or optimizes travel time or cost)
dynamic assignment
similar to user equilibrium, but this method assigns trips over time as well
incremental assignment methods
assignment by link or node – assign increment of flow and then update travel times, then assign another increment of flow on new shortest time
Basics of urban planning theory.
planner’s objective is not merely to describe the city and its components, but rather to propose ways in which they can be changed,
3 basic concepts used to describe urban form
urban form, urban interaction, and urban spatial structure).
urban form
the spatial pattern or “arrangement” of\nindividual elements
urban interaction
collective set of interrelationships, linkages, and flows (i.e., highways and streets)
urban spatial structure
Combines the urban form through the urban interaction with a set of\norganizational rules into a city system (i.e., rent, density, income)
Comprehensive plan, master plan, or general plan:
An official statement of a geographic unit’s policies and intentions pertaining to physical development in\nthe years ahead.
Guidelines:
set of implementation techniques
Legislation:
Recommendations turned into bills and\nenacted into law
Codes
Housing and building codes, for example. Important implementation techniques for ensuring the quality of community growth. Establish\nstandards. Used at the local municipal level.
Zoning:
Legal device for implementing local land–use plans. Ensures compatibility and controls the densities of certain parts of the community
Subdivision regulations:
Regulations that complement the local zoning ordinances. Control the development and change occurring within a community
Infrastructure
the life–support facilities of a\ngeographic unit, like, streets, bridges, sewers, rails, etc.
4 specific types of land use models as outlined in Meyer & Miller’s text and the basis for each
heuristic, simulation, operational, and scenario
3 values calculated in Hansen’s Accessibility Model
Accessibility index, development potential, and population allocated to a zone
2 types of assessment to determine transportation impacts on the urban activity system & define
ex post assessment – evaluate current condition with previous one “before and after”\npriori assessment – with and without level of analysis, only uses forecasted data
3 levels of decision making outlined for supply analysis.
Metropolitan–level network analysis for strategic investment, Operational or tactical planning, Scheduling of transportation services
5 major components of a transportation system and the interaction between these components.
system user, mode, infrastructure, intermodal connections, stakeholders
6 performance characteristics and measures used in transportation
speed, volume, density, capacity, level of service, headway
4 exclusive right–of–way or guideway operations
performance, headway, capacity, dwell time
Shared right–of–way operations (controlled vs. uncontrolled facilities).
controlled facilities – freeways, uncontrolled – urban\nstreets and sidewalks
5 principles of pedestrian flow
comfort, convenience, safety, security, economy
pedestrian flow definition– comfort
weather protection, climate control, shelters
pedestrian flow definition– convenience
walking distances, pathway\ndirectness, grades, sidewalk ramps, signing, maps
pedestrian flow definition– safety
separation of pedestrians from vehicular traffic on the same horizontal plan
pedestrian flow definition– security
lighting, open lines of sight, degree of\nstreet activity
pedestrian flow definition– economy
user costs incurred by travel delay\nand inconveniences, commercial development influenced by pedestrian activity
pedestrian flow concepts (equation)
pedestrian unit flow rate = peak 15min flow rate / (15 * effective width of sidewalk)
Network flow analysis (3 ways it can be used)
used to determine maximum flow through a networkwith links of finite capacity, equilibrium flow through a\nnetwork, given a known set of origin–destination patterns, shortest paths between nodes within the network
