Last modified by Reya Jasmin on 2025/01/22 21:18
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1 = SIRI MonitoredVehicleJourney Element =
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3 The SIRI ##MonitoredVehicleJourney## element contains most of the relevant real-time information about particular vehicles in the MTA Bus Time system. It is used by the responses to both the [[VehicleMonitoring>>Developers.SIRIVehicleMonitoring]] and [[StopMonitoring>>Developers.SIRIStopMonitoring]] calls. As much as possible, the values in a ##MonitoredVehicleJourney## element correspond to the values in the MTA's GTFS data.
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5 The XML below illustrates the SIRI MonitoredVehicleJourney element. Other notes on the contents of a ##MonitoredVehicleJourney## follow the example.
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10 ##<MonitoredVehicleJourney>
11 \\\\ <!~-~- The 'fully qualified' route name (GTFS agency ID + route ID) for the trip the vehicle is serving. Not intended to be customer-facing. ~-~->
12 <LineRef>MTA NYCT_B63</LineRef>
13 \\\\ <!~-~- The GTFS direction for the trip the vehicle is serving ~-~->
14 <DirectionRef>1</DirectionRef>
15 \\\\ <!~-~- A compound element uniquely identifying the trip the vehicle is serving ~-~->
16 <FramedVehicleJourneyRef>
17 \\\\ <!~-~- The GTFS service date for the trip the vehicle is serving ~-~->
18 <DataFrameRef>2011-01-28</DataFrameRef>
19 \\\\ <!~-~- The GTFS trip ID for trip the vehicle is serving, prefixed by the GTFS agency ID ~-~->
20 <DatedVehicleJourneyRef>MTA NYCT_20110102EA_087800_B63_0002_B63_19</DatedVehicleJourneyRef>
21 </FramedVehicleJourneyRef>
22 \\\\ <!~-~- The GTFS Shape_ID, prefixed by GTFS Agency ID ~-~->
23 <JourneyPatternRef>MTA NYCT_B630152</JourneyPatternRef>
24 \\\\ <!~-~- The GTFS route_short_name ~-~->
25 <PublishedLineName>B63</PublishedLineName>
26 \\\\ <!~-~- GTFS Agency_ID ~-~->
27 <OperatorRef>MTA NYCT</OperatorRef>
28 \\\\ <!~-~- The GTFS stop ID for the first stop on the trip the vehicle is serving, prefixed by Agency ID ~-~->
29 <OriginRef>MTA_801131</OriginRef>
30 \\\\ <!~-~- The GTFS stop ID for the last stop on the trip the vehicle is serving, prefixed by Agency ID ~-~->
31 <DestinationRef>MTA_801042</DestinationRef>
32 \\\\ <!~-~- The GTFS trip_headsign for the trip the vehicle is serving ~-~->
33 <DestinationName>BAY RIDGE SHORE RD via 5 AV</DestinationName>
34 \\\\ <!~-~- If a bus has not yet departed, OriginAimedDepartureTime indicates the scheduled departure time of that bus from that terminal in ISO8601 format ~-~->
35 <OriginAimedDepartureTime>2011-01-28T14:45:00.000-04:00 </OriginAimedDepartureTime>
36 \\\\ <!~-~- SituationRef, present only if there is an active service alert covering this call ~-~->
37 <SituationRef>
38 <SituationSimpleRef>MTA NYCT_8d065d76-2813-46ee-b024-20f956232831</SituationSimpleRef>
39 </SituationRef>
40 \\\\ <!~-~- Always true ~-~->
41 <Monitored>true</Monitored>
42 \\\\ <!~-~- The most recently recorded or inferred coordinates of this vehicle ~-~->
43 <VehicleLocation>
44 <Longitude>-73.97857</Longitude>
45 <Latitude>40.68448</Latitude>
46 </VehicleLocation>
47 \\\\ <!~-~- Vehicle bearing: 0 is East, increments counter-clockwise ~-~->
48 <Bearing>345.7</Bearing>
49 \\\\ <!~-~- Indicator of whether the bus is making progress (i.e. moving, generally), not moving (with value noProgress), laying over before beginning a trip (value layover), or serving a trip prior to one which will arrive (prevTrip). ~-~->
50 <ProgressRate>normalProgress</ProgressRate>
51 \\\\ <!~-~- Optional indicator of vehicle progress status.  Set to "layover" when the bus is in a layover waiting for its next trip to start at a terminal, "spooking" which means a bus is in revenue service, but it is not transmitting real time data (in this case it will use schedule data including schedule deviation), and/or "prevTrip" when the bus is currently serving the previous trip and the information presented 'wraps around' to the following scheduled trip. ~-~->
52 <ProgressStatus>layover</ProgressStatus>
53 \\\\ <!~-~- Optional indicator of whether the bus occupancy is deemed to be "full","seatsAvailable" or "standingAvailable". If bus occupancy information is not available, this indicator is not shown (aka hidden.) ~-~->
54 <Occupancy>seatsAvailable</Occupancy>
55 \\\\ <!~-~- The vehicle ID, preceded by the GTFS agency ID ~-~->
56 <VehicleRef>MTA NYCT_7582</VehicleRef>
57 \\\\ <!~-~- Depending on the system's level of confidence, the GTFS block_id the bus is serving. Please see "Transparency of Block vs. Trip-Level Assignment" section below ~-~->
58 <BlockRef>MTA NYCT_20120902CE_JG_24900_B35-26-JG_1503</BlockRef>
59 \\\\ <!~-~- Call data about a particular stop ~-~->
60 <!~-~- In StopMonitoring, it is the stop of interest; in VehicleMonitoring it is the next stop the bus will make. ~-~->
61 \\\\ <MonitoredCall>
62 \\\\ <!~-~- The GTFS stop ID of the stop prefixed by agency_id ~-~->
63 <StopPointRef>MTA_308214</StopPointRef>
64 \\\\ <!~-~- The ordinal value of the visit of this vehicle to this stop, always 1 in this implementation ~-~->
65 <VisitNumber>1</VisitNumber>
66 \\\\ <!~-~- Predicted arrival/departure times in ISO8601 format ~-~->
67 <ExpectedArrivalTime>2015-06-04T10:46:08.361-04:00</ExpectedArrivalTime>
68 <ExpectedDepartureTime>2015-06-04T10:46:08.361-04:00</ExpectedDepartureTime>
69 \\\\ <!~-~- SIRI container for extensions to the standard ~-~->
70 <Extensions>
71 \\\\ <!~-~- The MTA Bus Time extensions to show distance of the vehicle from the stop ~-~->
72 <Distances>
73 \\\\ <!~-~- The distance of the stop from the beginning of the trip/route ~-~->
74 <CallDistanceAlongRoute>3038.9</CallDistanceAlongRoute>
75 \\\\ <!~-~- The distance from the vehicle to the stop along the route, in meters ~-~->
76 <DistanceFromCall>1101.7</DistanceFromCall>
77 \\\\ <!~-~- The distance displayed in the UI, see below for an additional note ~-~->
78 <PresentableDistance>5 stops away</PresentableDistance>
79 \\\\ <!~-~- The number of stops on the vehicle's current trip until the stop in question, starting from 0 ~-~->
80 <StopsFromCall>5</StopsFromCall>
81 </Distances>
82 </Extensions>
83 \\\\ </MonitoredCall>
84 \\\\ <!~-~- The collection of calls that a vehicle is going to make. ~-~->
85 <OnwardCalls>
86 \\\\ <!~-~- A stop that the vehicle is going to make, if the detailLevel is set to calls ~-~->
87 <OnwardCall>
88 \\\\ <!~-~- The GTFS stop ID of the stop ~-~->
89 <StopPointRef>MTA_308215</StopPointRef>
90 \\\\ <!~-~- The ordinal value of the visit of this vehicle to this stop, always 1 in this implementation ~-~->
91 <VisitNumber>1</VisitNumber>
92 \\\\ <!~-~- The GTFS stop name of the stop ~-~->
93 <StopPointName>5 AV - GARFIELD PL</StopPointName>
94 \\\\ <!~-~- SIRI container for extensions to the standard ~-~->
95 <Extensions>
96 \\\\ <!~-~- The MTA Bus Time extensions to show distance of the vehicle from the stop ~-~->
97 <Distances>
98 \\\\ <!~-~- The distance of the stop from the beginning of the trip/route ~-~->
99 <CallDistanceAlongRoute>3267.1</CallDistanceAlongRoute>
100 \\\\ <!~-~- The distance from the vehicle to the stop along the route, in meters ~-~->
101 <DistanceFromCall>1329.9</DistanceFromCall>
102 \\\\ <!~-~- The distance displayed in the UI ~-~->
103 <PresentableDistance>6 stops away</PresentableDistance>
104 \\\\ <!~-~- The number of stops on the vehicle's current trip until the stop in question, starting from 0 ~-~->
105 <StopsFromCall>6</StopsFromCall>
106 </Distances>
107 </Extensions>
108 \\\\ </OnwardCall>
109 \\\\ ... more OnwardCalls
110 \\\\ </OnwardCalls>
111 </MonitoredVehicleJourney>##
112
113 === The PresentableDistance field: ===
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115 The logic that determines whether stops or miles are shown in the PresentableDistance field is below:
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117 show distance in miles if and only if:
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119 ##(distance in miles to _immediate next stop_ is > D) OR (distance in stops to current stop is > N AND distance in miles to current stop > E)##
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121 in other words, show distance in stops if and only if (the below is just the inverse of the above, according to DeMorgan's law):
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123 ##(distance in miles to _immediate next stop_ is <= D) AND (distance in stops to current stop <= N OR distance in miles to current stop <= E)##
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125 Show "approaching" if and only if:
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127 ##distance_in_miles to immediate next stop < P##
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129 show "at stop" if and only if:
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131 ##distance_in_miles to immediate next stop < T##
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133 Current Parameter Values:
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135 |=Parameter|=Value   
136 |D| .5 miles
137 |N| 3 stops
138 |E| .5 miles
139 |P| 500 feet
140 |T| 100 feet
141
142 === Transparency of Block vs. Trip-Level Assignment ===
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144 MTA Bus Time tries to assign buses to blocks- a sequence of trips that start and end at a depot. This allows the system to make a statement about what a bus will do after it reaches the end of its current trip. 
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146 However, there is not always enough affirmative and corresponding evidence to make such a strong statement. In this case, MTA Bus Time falls back to a trip-level assignment, where it just picks a trip from the schedule that is representative of the route and stopping pattern that the bus is likely to pursue.
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148 The SIRI API now reflects this distinction as described here and in other items below. If the assignment is block-level, the new ##BlockRef## field of the ##MonitoredVehicleJourney## is present, and populated with the assigned block id.