User`s manual

11-3
Chapter 11 — Roundabout Movement Studies
and u-turn movements from each of the four approach directions. If a car
makes a right movement from an approach, you simply push the button that
shows a right movement from that direction. The TDC Ultra keeps track of
everything else for you.
The TDC Ultra can also double or triple the number of movements counted
from 16 to 32 or 48 by using the unit’s two BANK keys in conjunction with
the regular movement keys. If a movement key is pressed, the count is reg-
istered in the “primary” movements (1-16). If the BANK1 key is held down
while a movement key is pressed, the count is registered in the “secondary”
movements (17-32). If the BANK2 key is held down while a movement
key is pressed, the count is registered in the “tertiary” movements (33-48).
Normally, the turning movements of less common events are counted with
the secondary and tertiary (BANK1 and BANK2) keys.
The secondary and tertiary keys are often assigned to truck movements. For
example, if a car makes a right movement from the north approach, then
you press button #2. If a light truck makes the same movement, you press
and hold down the BANK 1 key while pressing button #2, which is counted
in the secondary movements. If a heavy truck makes the same movement,
you press and hold down the BANK 2 key while pressing button #2, which
is counted in the tertiary movements. Since it takes a little more work to
press the BANK 1 and BANK 2 keys, the less common truck volumes are
assigned to the secondary movements.
When this data is processed using the PETRAPro software, you can get
percentage breakdowns of the data based on the different groups.
This is just one example of how the Bank keys can be used. They can also be
used for counting additional approaches if you have more than the standard
four at an intersection.