If I as a pedestrian/motorcyclist/car-driver assume such things, eg that people not using turn indicators aren't turning then I'd have an accident at least once a day.

Making a couple of second allowance to protect the lives of other road users seems reasonable to me.

That said I don't live in an area with high cycle use - in the small UK city I'm in you're more likely to be stopping to avoid a drunk or a teenage boy doing wheelies.

>and runs into me //

Cleverly worded, but if you use your mirrors properly ... what's that phrase "hell is other road-users"?

The highway code says that cyclists should stay to the left. Even on a roundabout with multiple lanes, cyclists are supposed to stay to the left and cycle across exits.

I don't ever follow that rule when cycling, it does seem dangerous, but it is the rule, regardless of whether you disagree. You should always check blind spots when turning left, and you should have been coached to do this when learning to drive.

> The highway code says that cyclists should stay to the left.

The uniform vehicle code (which is the basis of many state road rules in the US) states the following:

>> Any person operating a bicycle... shall ride as close as practicable to the right-hand curb or edge of the roadway except under any of the following situations

>> [...]

>> When reasonably necessary to avoid conditions including [...] substandard width lanes that make it unsafe to continue along the right-hand curb or edge. For purposes of this section, a "substandard width lane" is a lane that is too narrow for a bicycle and a motor vehicle to travel safely side by side within the lane.

A cyclist riding as close to the edge of a given lane as practicable will leave roughly 2 feet between the edge of the bicycle's handlebar and the edge of the lane. The cyclist is about 2 feet wide. In a lot of states in the US, there is a requirement that a least 3 feet of space is left between the cyclist and the overtaking vehicle.

2 + 2 + 3 = 7 feet. A passenger vehicle in the US is about 6 feet wide. A commercial vehicle (e.g., truck/lorry or bus) is about 8.5 feet wide. The typical lane width ranges from 10 to 12 feet. For a 10 foot wide lane, a cyclist taking up 7 feet of space only leaves 3 feet of space for a 6 to 8.5 foot wide vehicle (5 feet for 12 foot wide lanes). That means that the two vehicles cannot safely travel side-by-side within the lane.

So, according to the UVC, there isn't a requirement to keep toward the edge of the lane in most cases.

I haven't checked to see whether the UK highway code has a similar exception to the "stay to the left part of the lane" rule.

The other problem with keeping towards the edge of the lane as opposed to riding near the middle is that the cyclist is less visible to overtaking, cross, and oncoming traffic because they're hidden by other motor vehicles or not in the field of view of a lot of drivers.

I completely agree. There are similar rules over here about leaving a gap to the kerb, and that there should also be a gap left by overtaking vehicles. Both are often not observed.

Here's the (brief) rules for roundabouts: http://www.highwaycodeuk.co.uk/rules-for-cyclists-roundabout...

Most cycling proficiency courses here in the UK will tell cyclists to ride more centrally when in a narrow lane, which is good advice. A cyclist is also legally allowed to do that.

It gets a bit fuzzy though when there's a cycle lane provided.

> It gets a bit fuzzy though when there's a cycle lane provided.

A lot of times, the cycle lane is really too narrow to safely ride in. It really ought to be a minimum of 4 feet wide (allowing a 1 foot space on each side of the cyclist if they're centered in the lane. Some that I've seen aren't even as wide as the handlebars on the bike.

Where I live, a cyclist isn't required to use the cycle lane even if one is present. Do you know whether the same applies in the UK?

You don't have to use a cycle lane here, but there have been cases in recent years where police have incorrectly stopped/charged someone for not using a cycle lane.

Should be; and as a driver, rider, and cyclist, would absolutely love to transport myself through such a world. Alas, a twenty-minute drive yesterday got me: people turning right from a left lane (across the through and right lanes, no less), people driving straight through red lights, pedestrians nearly run over on their green light by drivers turning into them, not to mention no indicator lights at all, and 10% of cars driving without any lights at all at night. (Incidentally, "world has road standards and then just ignores them" is IMHO the #1 reason that self-driving cars are not in our near future)

> If I, as a driver, see someone in a left-only lane, it should be absolutely safe for me to assume that they are indeed turning left

The highway code is a bit more nuanced than you on this topic: http://www.highwaycodeuk.co.uk/road-junctions.html

it is safer for the vehicle driver to not make that assumption, it is safer for the cyclist not to be in that position as you point out; and primarily, it is safer if the road layout does not put these different vehicles in the same space.