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Cafer Avcı edited this page Dec 9, 2021 · 1 revision

How to model work zone

learning goals: understand the key connections among link, link performance, path, trajectory understand the connection between path flow volume and individual agents in agent.csv, for the same OD pair.
understand the difference between routing and simulation, routing engine provides the path as the input into simulator, when we computer shortest path, a set of link travel times are used, e.g. VDF form.

simulation engines (i.e. network loading) uses the precomputed path (from the routing engine) to simulate the detailed space time trajectory (timestamps) for vehicles

how do we check if a path used in the vehicle travels through a workzone area or not...

  1. basic data files: node.csv, link.csv, (capacity used in simulation, VDF_capk used in routing/asssignment) setting.csv (assignment_mode = dta), agent types include sov, info, vms demand_period, e.g. AM demand file (column, path, matrix)

  2. scenario.csv 2.1 basic data structure for simulation from_node_id, to_node_id, capacity (reduced capacity), time_period

the format of time_period hhmm_hhmm (24 military time)

2.2.basic data structure for routing demand_period lr_price_(agent_type) e.g. lr_price_sov, lr_price_info: for the initial price

lr_rt_price_(agent_type) for the real time information

Hints: use nexta tool -> use subarea selection tool ("s+" toolbar) -> the selected link set id displayed at subarea_link.csv under the same folder.

  1. run DTALite.exe link_performance.csv (mainly from routing engine, travel time is computed through the volume delay function + LR price) e.g. for this link: 22726->22370

speed is still free-flow (60 miles per hour), travel time has no delay, because there is no volume passing through this link with closure. the zero link volume is further due to the impact of routing with lr_price_sov = 9999 for this link

TD_link_performance.csv (mainly from simulation engine, travel time is computed as a result of simulation) path.csv

go to path file, check node_sequence, and link_sequence link_sequence outputs the link_id

there are two ways for you to check if a path travelled by vehicles passes a work zone impact area or not.

  1. tag link_id for workzone as workzone1, workzone2, so the link_sequence output in path.csv will show the content in link_sequence field.

hands-on steps: a. use excel function to build the link key and use vlookup to tag the links in the work zone as wz1, wz2, . b. run ue mode with 1 iteration, you can see the routing information 2. use nexta to check

trajectory.csv

hands_on steps change td_link_performance_sampling_interval_in_min = 5 in setting.csv

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