Ultra Start 15xx Bedienungsanleitung PDF herunterladen (Seite 73)

8-5

What Data Do You Need to Collect?

There are three ways of collecting data for saturation ﬂow studies. The ﬁrst

is a basic study where you assume all cars are part of the saturation ﬂow (i.e.

all vehicles recorded with the 1C-4C keys were in the queue at the start of

green). No signal timings or arrival types can be calculated. The second is

similar to the ﬁrst, except that signal timing is recorded. Finally, the third

study records all the data, including signal timing and arrival types. These

different types of data collection are described below.

Type 1 – Saturation Flow Only

In the saturation ﬂow only study, you will collect just enough data to

calculate saturation ﬂow rates. You will not be able to produce signal

timings or arrival types, but the data collected is very easy. Collect the

data as outlined below:

1. Wait for the signal controlling the approach you are studying

to turn red.

2. Watch the queue begin building, as well as the opposing signal

for the cycle change.

3. When the signal turns green, press the GREEN key.

4. As each queued vehicle crosses the stop bar, press keys 1C - 4C

that corresponds to the lane that the vehicle is in.

5. Continue pressing keys 1C-4C until the last queued vehicle

crosses the stop bar.

6. If you have enough samples, turn the TDC Ultra or go back to

step 2 to record more data.

Type 2 – Saturation Flow with Signal Timing

This study is very similar to the Saturation Flow Only study. The dif-

ference here is that you will also record signal timing. The data col-

lection is a little more difﬁcult, because you have to carefully watch

for the signal to change.

1. Wait for the signal controlling the approach you are studying

to turn red.

2. Watch the queue begin building, as well as the opposing signal

for the cycle change.

3. When the signal turns green, press the GREEN Key.

4. As each queued vehicle crosses the stop bar, press keys 1C-4C

that corresponds to the lane that the vehicle is in. You must also keep

a close eye on the signal to determine the next phase change.

Chapter 8 — Saturation Flow Rate Studies

1 2 ... 68 69 70 71 72 73 74 75 76 77 78 ... 123 124

Keine Kommentare

Ultra Start 15xx Bedienungsanleitung Seite 73