exam1 Flashcards
Which categories of an urban street must be identified, if FFS measurements are not available?
the street’s functional and design categories must be used to identify its class.
Which parameter describes in the HCM the quality of the progression of signalized intersections?
Arrival type (AT) Running Time, TR [km/s] and control delay
Which are the two components of the total travel time on a segment of an urban street?
Running time Control delay (at signalized intersection)
Which different segments could a freeway facility contain?
Connected segments:
Basic freeway segment
Ramp segment
Weaving segments
Which are the two primary types of traffic signal control
- Pretimed signals* (fixed): At pretimed traffic signals each signal phase or traffic movement is serviced in a programmed sequence that is repeated throughout the day.
- Actuates Signals*: Actuated signal control differs from pretimed in that it requires “actuation” by a vehicle or pedestrian in order for certain phases or traffic movements to be serviced.
Describe LOS
The LOS are defined to represent reasonable ranges in the three critical flow variables: speed, density and flow rate.
LOS A
describes free-flow operations. Free-flow speeds prevail. Vehicles are almost completely unimpeded in their ability to maneuver within the traffic stream.>72
LOS B
represents reasonably free-flow and free-flow speeds are maintained. The ability to maneuver within the traffic stream is only slightly restricted.>56-72
LOS C
provides for flow with speeds at or near the FFS of the freeway. Freedom to maneuver within the traffic stream is noticeably restricted and lane changes require more care and vigilance on the part of the driver.>40-56
LOS D
is the level at which speeds begin to decline slightly with increasing flows and density begins to increase somewhat more quickly. Freedom to maneuver within the traffic stream is more noticeably limited.>32-40
LOS E
describes operation at capacity at the highest density value. Vehicles are closely spaced, leaving little room to maneuver within the traffic stream at speeds that still exceed 80 km/h. At capacity, the traffic stream has no ability to dissipate even the most minor disruption and any incident can be expected to produce a serious breakdown with extensive queuing Maneuverability within the traffic stream is extremely limited.>26-32
LOS F
describes breakdowns in vehicular flow. Such conditions generally exist within queues forming behind breakdown points.
Please describe the 6 main steps of a Sustainable Development Analysis
Definition of scenarios incl. time horizon,
definition of indicators,
definition of objectives (upper and lower limit ) and the shape of the value function,
determination of the quantitiative effects singel indicators
Weighting of the different single indicators of the different single indicators.
Synthesis of part-indices to an index for sustainable development.
Please describe at least 4 factors that appear to be decisive in securing travel behavior changes as elements of the Australian TravelSmart Projects (individual marketing)
personal engagement at a one-to-one, household or local workplace level
functional materials—such as public transport tickets, maps, and timetables—that allow people to explore new travel options, plan and make decisions
support of local leaders—councils, senior company management, school boards
whole-of-community involvement—larger interventions appear to have larger results, suggesting that individuals are supporting and reinforcing each others’ behaviour
removing incentives for car travel, penalising car use, or rewarding ‘green’ alternatives.
Please draw a graph explaining the three dimensions, transport is embedded, with regard to sustainability and specify the relevant variables, which are describing the relation in each direction.
Society: habits and lifestyle - mobility communication
economy: time-saving accessibility - investment infrastructure needs
ecology: environmental impacts - natural resources
