Your previous comment was mainly referring to traffic speed which is primarily a function of geometric design of the road (width, superelevation, sightlines, etc).

> Pavement markings, including lane widths,

With commercial vehicle traffic, lane widths cannot be more narrow than the vehicle. At the body, a commerical vehicle is 8.5 feet wide. Adding mirror width makes them over 10 feet wide. In any case, looking at the scatter plot in this particular study[1], you can see that the 85th percentile speed doesn't really change regardless of whether the width is closer to 10 feet or 12 feet (the 85th percentile speeds ranged from 37 to 50 mph in both cases

> bike lanes,

The MUTCD doesn't really specify the minimum width of a bike lane, but the AASTHO Guide for the Development of Bicycle Facilities does specify a minimum usable pavement width of 4 feet, despite the fact that they say that a cyclist has an operating width of 5 feet.

The MUTCD, unfortunately, allows for a straight through bike like to the right of a general purpose lane that allows for right turning traffic, which leads to the situation that increases the risk of right hook collisions for cyclists. NACTO does not really address that problem with conventional bike lanes as far as I've seen.

> counter flow bike lanes

These shouldn't be allowed mainly because vehicular traffic will not be looking in the direction that counter flow cyclists are coming from and will fail to yield to them as can be seen here[2]. The other problem with contraflow bike lanes is that it increases the cyclists exposure to glare from automotive headlamps because the standard asymmetric beam pattern directs more light to the right and allows for a higher horizontal cutoff. This can basically make it very difficult for cyclists to see where they're going and will make it difficult, if not impossible to spot road hazards in time to avoid them.

> My largest personal pet peeves with the MTUCD is the requirement for far side signal heads. Far side signal heads cause crosswalk encroachment. If signals were near side only like in EU, crosswalk encroachment would be impossible because you lose sight of the signal head.

Wouldn't that lead to more red light running?

> https://www.regulations.gov/comment/FHWA-2020-0001-0258

>> The draft 11th Edition of the MUTCD takes away tools that engineers can use to improve mobility and safety for vulnerable users in challenging and complex urban settings, such as counter flow bike lanes next to parallel parking and the use of HAWK signals (Pedestrian Hybrid Beacons) with bike signals. Lack of these treatments will make many locations more dangerous and harder to access by vulnerable road users

One difference between cyclists and walking pedestrians is that cyclists move much faster. This means that they're further from the intersection when a motorist is making a turn in a situation where they may need to yield.

Normally, a pedestrian is very close to entering the intersection, meaning that a motorist can see them without having to turn their head to look down the sidewalk/path to check for any approaching pedestrians. On the other hand, a cyclist could be 30 feet away from getting to the intersection and out of sight of the motorist unless the motorist makes a conscious effort to look down the sidewalk/path in order to see any approaching cyclist. Most motorists aren't going to do the latter, which means that cyclists are at increased risk of a collision in those situations.

The best option is to enforce protected movements through the intersections with traffic signals and not rely in yielding at all. Unfortunately, most pedestrian and cyclist facilities rely on mutual yielding between them and motorists, which doesn't really work out that well. But if we were to use signals, then everyone will experience significantly more delay and there would be a problem with non-compliance with the signals.

[1] https://nacto.org/docs/usdg/review_lane_width_and_speed_pars... (figure on page 6)

[2] https://www.youtube.com/watch?v=4k6-AI_X1qE