Knucklehead driving

In my role as a frequent utiliser of transport infrastructure, I've just completed a detailed study of knucklehead driving on Australia's roads.  I have identified important independent risk factors for knucklehead driving.  Knucklehead driving includes behaviours such as:

• tailgating,
• passing on the left in a turning lane at an intersection,
• changing lanes without signalling,
• weaving through traffic,
  
• egregious acceleration,
• gratuitous overtaking so as to never be behind another vehicle no matter how fast it is travelling,
  
• speeding, especially in built-up areas.

Knucklehead driving is distinct from hat-driving.  Hat-driving includes behaviours such as:

• struggling to park on a busy street,
• going slowly in the passing lane,
• not realizing the traffic lights have changed,
  
• dithering when turning into traffic or merging.
  

To assess a driver's risk of displaying knucklehead behaviors, carefully examine the vehicle in question and use this score chart:

Spoiler?  +1
Very large spoiler? +2
Very small penis? +3
Ute +1 (excludes utes actually carrying goods or equipment, including all tray-tops)
Ute with dog in back? +1 more
Station wagon? -4
"Sports" station wagon? +2 instead
Motor scooter? -10
Bullbar? +1
Bullbar on car in metropolitan area? +1 more
Bright yellow? +2
Bright green? +2
Bright purple? +1
Bright red? +1
Chameleon paint? +3
Bumper stickers with anti-immigration sentiments? +2
Bumper stickers with Southern Cross? +1
Bumper sticker with "Magic Happens"? +1
Shiny wheels? +1
Low profile tyres? +1
Lowered suspension? +2
Multiple exhausts? +1 per pipe after the first
Holden? +2
HSV Holden? +2 more
Ford Falcon? +1
Subaru WRX? +2
Subaru Liberty, Forrester or Outback? -5
Driver male? +2
Driver on P-plates? +2
Driver wearing singlet? +1
Driver shirtless? +3
Driver's seat reclined at greater than 60 degrees? +1
Driver barely able to see above steering wheel despite being of apparently normal stature? +2
Driver has only one hand on the wheel? +1
Tinted windows? +1
Windows down? +1
Driver has arm out window? +1
Driver has head out window? +2
Passenger has feet on dash? +1
Driver has feet on dash? +5
Custom plates? +2
Custom plates that match the colour of the vehicle? +2 more
Custom plates with clumsily executed sexual innuendo that it takes more than 10 seconds to decipher? +3 more

Add up all the scores then look up the total in the chart below to find the risk of knuckleheaded driving and your appropriate response.

• Less than 3: Sensible driver, though may be at increased risk of hat-driving.  No follow-up necessary.
  
• 4-8: Isolated infuriating incidents may occur.  Some tut-tutting and/or head-shaking may be required.
• 9-12: Infuriating incidents likely.  Swearing will relieve tension.
  
• 13-16: Enraging incidents commonplace.  Consider either pre-emptive hat-driving or retaliatory knucklehead driving.
• 17 or greater: Knucklehead.  Nothing you do will help.  Next time catch the bus.