ML032510640
| ML032510640 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 05/31/2003 |
| From: | KLD Associates |
| To: | Entergy Nuclear Northeast, NRC/FSME |
| References | |
| NL-03-139 KLD TR-369 | |
| Download: ML032510640 (5) | |
Text
APPENDIX AGlossary of Traffic Engineering Terms Indian Point Energy CenterA-2KLD Associates, Inc.Evacuation Time EstimateRev. 1APPENDIX A: GLOSSARY OF TRAFFIC ENGINEERING TERMSTermDefinitionCapacityMaximum number of vehicles which have a reasonable expectation ofpassing a given section of roadway in one direction during a given time period under prevailing roadway and traffic conditions. These are estimates which are expressed as vehicles per hour (vph).CentroidAn origin or destination located in the interior of the EPZ.
ContentNumber of vehicles occupying a section of roadway at a particular pointin time.DestinationA location in the network, either within the interior or on the periphery,of the EPZ to which trips are attracted.Entry NodeA network node, that serves only as an origin. Vehicles are generatedthere and move onto the network to travel toward their respective
destinations.Exit NodeA network node, usually located on the periphery of a network, whichserves only as a destination. Vehicles that arrive at an exit node are discharged from the network.Green-Time to The ratio of the duration of a green interval to the signal cycle length.Cycle TimeThis ratio is the proportion of time available to service specified traffic Ratio (G/C Ratio)movement discharging from specified approaches to an intersection.Internal NodeAll nodes that are not Entry or Exit nodes. Vehicles travel through thesenodes from one link to the next along their respective paths toward their respective destinations.Level of ServiceAn index (A, B, ..., F) which is a qualitative descriptor of the operationalperformance of traffic on a section of roadway, usually expressed in terms of speed, travel time or density. In practice, each Level of Service index is often associated with a range of service volumes. This relation depends on the type of facility (freeway, rural road, urban street).
Indian Point Energy CenterA-3KLD Associates, Inc.Evacuation Time EstimateRev. 1TermDefinitionLinkA network link represents a specific, one-directional section of roadway. A link has both physical (length, number of lanes, topology, etc.) and operational (turn movement percentages, service rate, free-flow speed) characteristics.Measures of Statistics describing traffic operations on a roadway network.EffectivenessNodeA network node generally represents an intersection of network links. A node has control characteristics, i.e., the allocation of service time to each approach link.OriginA location in the network, either within the interior, or on the periphery,where trips are generated at a specified rate expressed in vehicles per hour (vph). These trips enter the roadway system to travel to their respective destinations.NetworkA graphical representation of the geometric topology of a physicalroadway system, which is comprised of directional links and nodes.Prevailing roadway Relate to the physical features of the roadway,and traffic conditionsthe nature (e.g., composition) of traffic on the roadway and the ambientconditions (weather, visibility, pavement conditions, etc.).Service RateMaximum rate at which vehicles, executing a specific turn maneuver, canbe discharged from a section of roadway at the prevailing conditions, expressed in vehicles per second (vps) or vehicles per hour (vph).Service VolumeMaximum number of vehicles which can pass over a section of roadwayin one direction during a specified time period with operating conditions at a specified Level of Service. (The Service Volume at Level of Service, E, approximates Capacity.) Service Volume is usually expressed as vehicles per hour (vph).Signal Cycle, The total elapsed time to display all signal indications, in sequence. TheCycle Time, Lengthcycle length is expressed in seconds.Signal IntervalA single combination of signal indications. The interval duration isexpressed in seconds. In general, a sequence of intervals comprise a signal phase.
Indian Point Energy CenterA-4KLD Associates, Inc.Evacuation Time EstimateRev. 1TermDefinitionSignal PhaseA set of signal indications (and intervals) which services a particularcombination of traffic movements on selected approaches to the intersection. The phase duration is expressed in seconds.Traffic AssignmentA process of assigning traffic to paths of travel in such a way as to satisfyall trip objectives (i.e., the desire of each vehicle to travel from a specified origin in the network to a specified destination) and to optimize some stated objective or combination of objectives. In general, the objective is stated in terms of minimizing a generalized "cost". For example, "cost" may be expressed in terms of travel time.Traffic DensityThe number of vehicles that occupy one lane of a roadway section ofspecified length at a point of time, expressed as vehicles per mile (vpm).Traffic DistributionA process for determining the destination of all traffic generated at theorigins. The result often takes the form of a Trip Table, which is a matrix of origin-destination traffic volumes.Traffic SimulationA computer model designed to replicate the real-world operation ofvehicles on a roadway network, so as to provide statistics describing traffic performance. These statistics are called Measures of Effectiveness.Traffic VolumeThe number of vehicles that pass over a section of roadway in onedirection, expressed in vehicles per hour (vph). Where applicable, traffic volume may be stratified by turn movement.Travel ModeDistinguishes between private auto, bus, rail and air travel modes.
Trip Table or A rectangular matrix or table, whose entries contain the numberOrigin-Destination of trips generated at each specified origin, during a specified time Matrixperiod, that are attracted to (and travel toward) each of its specifieddestinations. These values are expressed in vehicles per hour (vph) or
in vehicles.Turning CapacityThe capacity associated with that component of the traffic stream whichexecutes a specified turn maneuver from an approach at an intersection.