Every time he gets so close to a moving vehicle he risks becoming squished. I hope he has something really useful to do with the time he saves.
Phil
Filtering is part of their rider training course plus drivers are educated (generally) to watch out for bikes and let them through.
! No longer available
Motorcycle control rules
You must stay in control of your motorcycle at all times. You must sit with 1 leg on either side of your seat at all times when riding a motorcycle, but you can lift your leg from the footrests if you need to while riding.
Pillion passenger rules
A motorcycle passenger that sits behind the rider is called a pillion passenger.
You must only carry a passenger on a motorcycle if you:
hold a provisional or open licence for the class of motorcycle you are riding
and
you have held that licence for at least 1 year.
You must not carry pillion passengers, including your supervisor, at any time, if you hold a:
class RE learner licence
class RE provisional or open licence, but are riding a class R motorcycle in order to learn to ride that class of vehicle.
You must also not carry a pillion passenger for the first 12 months of holding a class RE or R provisional or open licence.
Rules for carrying passengers on any motorcycle
All of your passengers must wear an approved motorcycle helmet securely fastened.
Pillion passengers must be at least 8 years old and their feet must be able to reach the passenger footrests while seated.
You must not carry more passengers on the motorcycle or in the motorcycle's sidecar than the vehicle was designed to carry.
Your passenger must be seated safely on the pillion seat or in the sidecar.
Your pillion passenger must not ride on the motorcycle unless the motorcycle has a suitable pillion seat and suitable passenger footrests.
Your pillion passenger must face forwards and sit with a leg on either side of the seat, but is allowed to move a leg off the footrests to stretch or raise themselves from the seat.
Your passenger must not interfere with your effective control of the motorcycle. 
The above doesn't apply to the two UK clips posted which my comment was in relation too.
Just for interest - Pillion rules in SA aren't that strict. While on L plates we can have a pillion if they are a Qualified Driving Instructor (a Qualified Supervising Rider is a pillion passenger that holds an unconditional motorcycle licence for the preceding two years)
http://mylicence.sa.gov.au/my-motorcycle-licence/learners-permitNo restriction on having a pillion when you move on to R-date licence
http://mylicence.sa.gov.au/my-motorcycle-licence/r-date-class+Open or R Class
http://mylicence.sa.gov.au/my-motorcycle-licence/r-classOnly one pillion passenger may be carried and then only if the bike is fitted with proper footrests and seating
pillion passengers must always sit astride the seat facing forwards and with both feet on the footrests - See more at:
http://mylicence.sa.gov.au/road-rules/the-drivers-handbook/motorcycles#sthash.3Lx0Gt0C.dpuf Don't think SA has implemented the newer rider rules to apply to pillions yet.
