No important noticeable changes in Phase I or Phase II.
9.6.6.1 Phase III
NHTSA finally removed the language claiming a failure on the test is related to being drunk or impaired.
9.6.6.1.1 HGN
The officer now checks both eyes during each part of the test before moving on to the next part. The manual also now adds that the officer should use the full 4 seconds while measuring for onset prior to 45 degrees. If the stimulus is moved too fast, the officer may go past the point of onset[1]. The officer is now instructed to face the suspect away from flashing lights, but an artificial eye, or one eye is no longer an issue[2].
9.6.6.1.2 VGN
The officer must now hold the stimulus for 4 seconds at maximum deviation[3].
9.6.6.1.3 Walk and Turn
The officer no longer marks people off for not walking straight on the line as part of heel to toe[4].In regard to the instruction stance, feet must actually break apart to be counted as a clue[5].
Test conditions: No more visible line, or high line. But “high” is now “hard.” Now the line must be “designated”[6]. But, if the conditions do not exist, the suspect should be asked to perform it elsewhere, or only HGN should be used[7].
NHTSA raised the difficulty due to age to 65 and removed any difficulty due to being 50 pounds overweight (it must be nice to be an authoritative government agency and just replace numbers with ones that are more favorable).
“Walk and Turn requires a high, dry, level, nonslippery surface with sufficient room for the suspect to complete nine heel-to-toe steps. A straight line must be clearly visible on the surface.
Improper turn is now defined as: “The suspect removes the front foot from the line while turning. Record this clue if both feet are removed from the line. Also record this clue if the suspect clearly has not followed directions as demonstrate.[8]”
9.6.6.1.4 One Leg Stand
Instructions and scoring are primarily the same. However, the officer now marks: cannot do test if suspect puts foot down three or more times, and to record as 4 clues[9].
Interpretation – Age for difficulty to do test raised to 65, just like the WAT.
[1]Id at VIII-16
[2]Id at VIII-26
[3]Id at VIII-18
[4]Id at VIII-20
[5]Id at VIII-20
[6]Id at VIII-20
[7]Id.
[8]Id at VIII-20
[9]Id at VIII - 24