Drafting certainly can be effective at reducing drag and increasing range+efficiency.
However, it is dangerous, for these reasons:
- kicked up debris from long-haul truck wheels
- the obvious combination of low visibility and tight tolerance for error in the event of a hard braking situation or collision.
- the unstable condition in the drafting area where your power requirements reduce as you get closer, which means you're constantly making minor adjustments to maintain a suitable distance.
So, I've gradually focused on better fairings for headwinds and crosswinds instead of drafting. The Hollywood Electrics fairing mostly achieves that but needs a higher/touring windscreen to complete its role.
HOWEVER, there is one type of moderated drafting I've engaged in which seems sane and healthy:
- WHEN in a rough headwind+crosswind condition,
- THEN follow on the leeward / downwind side of a long-haul truck, staying visible in the driver's mirror on that side.
It is still a good idea to ensure enough distance to ensure good braking in an emergency. This "corner draft" is less unstable as well.
Mainly, I allow myself to do this when the winds are so gusty that the fatigue I'll accrue is more dangerous than the debris and stopping hazards, and making sure the driver can see me at least reduces their irritation at being followed.