Vehicle stream data file
The vehicle stream data files contain data which has been extracted
from raw data in the BHL database. Each vehicle stream data file
record indicates a matched pair of upstream and downstream transitions
from a specific lane at a specific station. Unmatched loop transitions
which are not resolved into a vehicle passing both the upstream
and downstream loops are discarded.
File name format
Vehicles-<year>-<month>-<day>-<starting_hour>
Sample vehicle stream data file entries
4 9 1727903 1727923 1727922 1727942
8 6 1727926 1727936 1727938 1727948
8 7 1727990 1727996 1728000 1728007
1 8 1727903 1727926 1727923 1727945
1 2 1727772 1727784 1727786 1727797
1 1 1727909 1727921 1727922 1727934
1 6 1727963 1727983 1727984 1728005
6 7 1727907 1727923 1727925 1727941
2 9 1727880 1727901 1727902 1727923 |
Field descriptions for vehicle stream data file records
Field 1: Station identification number
4 9
1727903 1727923 1727922 1727942
This field is the station identification number (currently
1 through 9) from which the data packet was received.
Field 2: Lane identification number
4 9
1727903 1727923 1727922 1727942
The lanes are numbered 0 to 9 with 0-4 being one side and
5-9 being the other. Stations 8 and 9 are different and I would
have to look it up to see what lanes correspond to what numbers.
Field 3: Upstream loop on time
4 9 1727903
1727923 1727922 1727942
This is the time, in 1/60 seconds since midnight on the
day indicated by the data file name, of the upstream loop "on"
event.
Field 4: Upstream loop off time
4 9 1727903 1727923
1727922 1727942
This is the time, in 1/60 seconds since midnight on the
day indicated by the data file name, of the upstream loop "off"
event.
Field 5: Downstream loop on time
4 9 727903 1727923 11727922
1727942
This is the time, in 1/60 seconds since midnight on the
day indicated by the data file name, of the downstream loop "on"
event.
Field 6: Downstream loop off time
4 9 1727903 1727923 1727922 1727942
This is the time, in 1/60 seconds since midnight on the
day indicated by the data file name, of the downstream loop "off"
event.
Notes
The first few lines of a data file may have negative times. We
suspect that this is correct and is due to situations where a later
loop transition is used by the processor to determine that an earlier
pair of pulses really were a vehicle. Or it could be a slight clock
error. In any case, the times of these entries are pretty close
to right (within a few seconds) and the later ones should be fine
to work with.
Return to the BHL data guide
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