Changes between Version 17 and Version 18 of TrafficModelATMSOverview

Timestamp:

02/27/2019 11:09:19 AM (7 years ago)

Author:

jdalbey

Comment:

Add highway map section

TrafficModelATMSOverview

@@ -19 +19 @@
      1. [#ourfep Our FEP Simulator]
    1. [#atmsdetail ATMS]
+ 1. [#highwaymap Highway Map]
  1. [#protocols Protocols]
    1. [#traffictofep Traffic Model to FEP Simulator]
@@ -74 +75 @@
 
 ==== Traffic Model Classes ==== #trafficmodelclasses
-The Highways and Highway classes were developed to give developers an abstraction of the traffic network that was feasible to work with. A Highway is undirected, meaning it does not have an associated (N/S/W/E) direction and represents traffic in both directions on the highway. A Highway is an aggregation of all of the Stations on a highway, sorted by postmile value. Stations do have an associated direction. Stations may or may not have Loop Detectors associated with the specified station direction, or the opposite specified direction. Hence, the undirected Highway abstraction. 
-
-''Update: ''As of r280 on Feb 26, 2019, "Station" now represents a Vehicle Detection Station, which is a logical grouping of all loop detectors for one direction.  So it DOES have an associated direction and all the loop detectors it monitors are going that direction.  Please refer to this diagram: [attachment:PeMS_data_sources.png PeMS data sources].
+The Highways and Highway classes were developed to give developers an abstraction of the traffic network that was feasible to work with. A Highway is undirected, meaning it does not have an associated (N/S/W/E) direction and represents traffic in both directions on the highway. A Highway is an aggregation of all of the Stations on a highway, sorted by postmile value. Stations do have an associated direction. Stations may or may not have Loop Detectors associated with the specified station direction, or the opposite specified direction. Hence, the undirected Highway abstraction.
+
+''Update: ''As of r280 on Feb 26, 2019, "Station" now represents a Vehicle Detection Station, which is a logical grouping of all loop detectors for one direction.  So it DOES have an associated direction and all the loop detectors it monitors are going that direction.  Please refer to this diagram: [attachment:PeMS_data_sources.png PeMS data sources].
 
 The Highways, Highway, and Station classes are all immutable. None of them contain dynamic data. The only class in the Highways model that contains dynamic values is the !LoopDetector class. The dynamic values in the !LoopDetector class are volume and occupancy. The volume field is an int, and the occupancy field is a float in the [0,1] range. The DOTCOLOR enum (specified in the !LoopDetector class) represents the colors shown on the ATMS Client (!Green/Yellow/Red). This enum supplies the necessary volume and occupancy values to achieve the desired display color for a Loop Detector.
@@ -100 +101 @@
 === ATMS === #atmsdetail
 The ATMS is a complete production server purchased from CalTrans. We were unable to find detailed documentation about ATMS features other than its ability to receive fep_reply structs via RPC and feed the received data to the ATMS Client interactive map GUI.
+
+== Highway Map File == #highwaymap
+When the simulation starts it creates the Highway Model by reading a preconfigured static data file we call the highway map file.  This file contains all the information needed to create the highway model described above:  VDS descriptors, FEP lines, and loop detector descriptors.  Currently it resides in `config/vds_data/highways_fullmap.txt`.
+
+To meet the need to easily create alternate highway map files to represent different regions of the real life highway network we created a Java tool called `BuildHighwayFile` in the `tmcsim.utilities` folder.  It merges info from three input files to create the highway map file:
+
+ 1. VDS file is the district VDS metadata file downloaded from the [http://pems.dot.ca.gov/?dnode=Clearinghouse PeMS Data Clearinghouse].  It gives identifying info about each VDS.  (The fields are tab delimited.)[[BR]]
+{{{
+ID    Fwy    Dir    District    County    City    State_PM    Abs_PM    Latitude    Longitude    Length    Type    Lanes    Name    User_ID_1
+1201044    133    S    12    59    36770    9    8.991    33.66184    -117.7553        OR    1    BARRANCA2    565       
+
+}}}
+
+ 1. Loop detector (lane) file that we found on the ATMS server. It lists all the lanes associated with each VDS. (The fields are space delimited, except for the last one.)
+{{{
+       FWY D CAL_POSTMILE     LDS_ID     VDS_ID    LOOP_ID LO       LANE LOOP_LOC
+       133 S            9    1201043    1201044    1201045 OR          1 RAMP ON
+}}}
+
+ 1. LDS file that has the fep line number for each LDS. (The fields are space delimited.)
+{{{
+    LDS_ID   LINE_NUM STN_ADDRESS LDS FREEWAY_ID D CAL_POSTMILE LDS_NAME            
+   1204192         74          14 170          5 S          .64 S LUIS REY
+}}}
+
+  The output highway map file lists VDS info and the lanes it governs in a format similar to what FEP simulator uses.
+
+{{{
+41
+44 0 23
+1204316 1 5 N 5.73 4 ESTRELLA1
+1204317 ML ML_1
+1204318 ML ML_2
+1204319 ML ML_3
+1204320 ML ML_4
+...
+
+}}}
+The output file format is chosen to make it easy to create the Traffic Conditions Messages need by the FEP Simulator (see next section).  However, if in the future the FEP Simulator and ATMS subsystems are deprecated the file format can be modified to be easily human readable by ordering it by highway and postmile instead of by FEP line. Note the loop detector info is included in the highway file for future expansion; currently the ATMS doesn't actually display lane-level details.
 
 == Protocols == #protocols