HarryStoddard

I'd have to say a motorcycle. Especially when the guy thinks he's macho and revs his engine when he's side by side with you.

uke

I was passed in the neighboring lane by a semi the other day. I knew it was coming (saw it as I turned into the right lane from the MUP), but it was still quite...intense watching it snake by on the left. Death is everywhere, man.

cudak888 

Not so bad - you can catch his draft as he goes by

-Kurt

JeffB502

Yesterday I was riding the shoulder around a gradual banked corner in a 2 lane 55mph zone with a double yellow line and saw a gravel truck (tractor with 2 trailers) passing another tractor trailer over the double yellow (both coming at me). The gravel truck's left tires were over the left line, into the shoulder I was riding on. I came to a complete stop at the far right edge of the pavement ready to jump into the dirt. The gravel truck driver edged over to the right so his left tires were only on the white line, not over it, but it was still pretty close considering how fast he was going. So yeah that's a new "scariest pass ever" for me lol. See here for Google Maps street view. I was on the far right side as pictured.

oscar2

+1 for the Harleys. Must be that small guy syndrome from being intimidated by cars themselves. They feel the need to take it out on us. I once had a Harley turn around twice to ride past me a total of 3 times just to make noise passing me. If I had spotted him sooner I could have reacted, but it's hard to tell looking back over your shoulder.
2nd would be anybody on a cell phone.

Foofy

Anyone who feels the need to honk their horn or yell at me to put on a helmet and/or get off the road.

cudak888 

Quoting the late, great Sheldon Brown:

-Kurt

ProsecutedBiker

Well i always commute back from high school, and so a lot of the people passing me are in 1970-80's rusty muscle cars with no muffler and HORRIBLE exhaust. The noise scares the **** out of me, and then I have to suck the putrid exhaust.

Saving Hawaii

You anti-car prick! Rusty muscle cars deserve the road more than you do, you're lucky we allow you to get anywhere on a bike at all.

zonatandem

A tractor trailer, not hauling a double, but a Triple trailer on a narrow bridge in Idaho at about 65mph . . . WOoooosh x 3 . . . while riding our tandem.
Saw/heard him coming and we sprinted, but bridge is over the Snake River; bridge is well over 1,000 ft. long.
Bit scary . . .

bpert

logging truck

ghettocruiser

School bus with busted "kid control arm" hanging out ten feet to the right.

BikeLover1989

1). Buses.
2). Big trucks
3). Cars with inconsiderate and distracted drivers on their cellphone.

Paul Barnard

Old folks seem deftly afraid of crossing the center line to effect a pass.

Ned_Detroit

Cars driven by idiots on the way back from Home Depot, Lowes, etc. who have 8' to 12' of lumber, conduit, trim moulding or some such sticking out of their passenger side window!! I've been walking on sidewalks and have been nearly hit by an idiot doing this. Jeeeesh!

BikeLover1989

^I work in a hardware store like Home Depot myself, and it AMAZES me how people can stuff such huge material in their small cars. There have not been any reports of stuff that sticks out the car window hitting people or other things, but I sure wouldn't be surprised if someone did, ESPECIALLY if a bike lane is to the right and a cyclist is going along. SCARY

OneArmedScissor

any pickup truck or car with a giant american flag sticker on the back.

without fail, the american flag wearers are the poorest example of the nationality.
I wish I had the bat-bicycle with top tube mounted grappling rocket launchers that would propel them out of this state and right to cuba.