The heirarchy of controls (the verison I'm familiar with is below) is not applied to road safety, and particularly not when it comes to vulnerable users. It is applied to some extent for the users of motorised vehicles.
The first think to do is eliminate the hazard. That means the removal of the large vehicles (hazard), full segregation of traffic, or limitations on the movement of traffic. Some segregation (like cycle lanes) are not elimination because they reduce exposure rather than removing the hazard.
It may be possible in some cases to replace the hazard with a lesser hazard or an alternative for of transport. I suspect that will be impractical in many cases.
This means to design in such way that either the hazard does not occur / is not required, or to ensure that people are not significantly exposed to the hazard. This could include the partial segregation of traffic, the redesign of a junction, or changing the design of vehicles to make them less hazardous.
These are rules and procedures. The sort of thing I was suggesting above (access only routes, risk assessments, spotters, etc.)
Protective equipment is the last thing on the list because it is only effective as a 'just in case' and in limited circumstances. PPE makes some sense when it is shown to be effective, and the hazard cannot otherwise be avoided or prevented. For example, it makes sense to wear safety glasses when using a sander or drill because they cannot be completely shielded without making them impractical with regards to their purpose.
The generall approach to road saety is that it is generally low risk to operate in traffic for all road users. However, the RTC rate is higher in some places, so we analyse accidents rates and look at how to reduce them.
We don't consider the transport system holistically. Most controls are applied from Engineering downward. And, many engineering solutions are considered too impractical or expensive.
“In some ways, it is easier to be a dissident, for then one is without responsibility.”
― Nelson Mandela, Long Walk to Freedom