Flow chart for making a conclusion
As you record the detection-to-arrival times for approaching vehicles, you can use this flow chart to help draw conclusions.
For a checklist with this flowchart and instructions, click here.
___ Was the warning time of any vehicle shorter than the crossing time?
- If YES, then this is a Situation of Uncertainty
(you cannot be confident that the next vehicle will give you enough warning).
- If NO, then consider the range of warning times:
___ Was the range of warning times close to the crossing time?
- If YES, then this is a Situation of Uncertainty
(Since your sample probably didn't include the full range, it is likely there will be vehicles with a warning time that is less than your crossing time).
- If NO, then consider the spread of the range:
___ Was the spread of the range of warning times broad?
- If YES, then this is a Situation of Uncertainty, unless there is a very significant difference between crossing time and the shortest warning time.
(When the sample of warning times has a wide range, it is quite likely that the actual range is even wider, so unless the difference between crossing time and the shortest warning time is very large, you can't be confident that there will never be vehicles with a warning time that is less than your crossing time).
- If NO, then this is a Situation of Confidence.
|