Just looking at Google maps for a short stretch of road with a service road that looks a bit like another one and using that as some sort of example as how right or wrong the speed limits on those roads is naïve at best and deliberately misleading at worst.
I agree - good job I didn't do that then!

In the case of the two Welsh roads, I drove along both of them (twice) over the weekend; had I not done so, I would not be aware of their existence (and thus would not be commenting about them in this thread). Meanwhile, the English road is one I am very familiar with, having probably travelled along it several thousand times (on foot, by car, and by bus).
Take the two examples:
1) on the A4059, the approach from the south of the section with the service road, there is a sweeping bend eastwards followed by a sharp bend back to northwards, with driveways on the inside of the bend where emerging vehicles cannot be seen clearly.
Indeed. The visibility and alignment of this particular section of the road is rather poorer than the original view which I linked. Prior to the recent change, this section had a 30 limit. It has warning signs indication both that there is a sharp curve, and that there is a junction on the inside of the curve, as well as white on black chevrons. Perhaps it could be accompanied by an advisory maximum speed sign (
like this. For the record, I am fully aware that this particular bit of road has no relevance to any of the others mentioned in this post; I have used it simply because it's the first place I could think of which has the kind of sign I'm referring to), but I don't think I've ever seen an advisory sign in a built up/residential area with a 30 limit so probably not appropriate here.
My opinion on these two corners would be that a speed limit of 30 would be appropriate (noting of course that it is a limit, not a target), as has been the case for decades, accompanied by appropriate warning signage.
Also, visibility of traffic or pedestrians at the most southerly link to the service road is poor.
I'm not sure if you mean traffic/pedestrians exiting the service road, or traffic passing on the main road. Regardless, I would disagree - there is over 100m clear visibility in both directions either side of the junction, with only two street lamp posts which might cause obstruction depending on the viewing angle.
Visibility from vehicles/pedestrians exiting the property accesses on the inside of the sharp corner is rather poor. This could be mitigated by installing some of those convex mirrors which are common across the country where visibility is poor. However, this is not an ideal solution.
Drive further north to the second link road where there is a community centre and a bit further north, a primary school.
Indeed, this was one of the things I noticed whilst driving along. This makes a substantial difference to any assessment of speeds (although it should be noted that for many areas of the country, a "
20mph when light flash" setup is considered adequate. Again, this example is simply the first one I could think of, not intended to form any comparison with the roads I am discussing here).
There are over 80 dwellings, mostly small family residences, on the roads that are fed by the service road with no local shops, so likely 200-300 residents that at various times will emerge in vehicles or walk from that area.
Agreed
2) on the A4184, the section that your link refers to has a service road to serve (as far as I can see) 23 dwellings. Looking at street view those houses are mostly pretty substantial - a fair proportion of them large detached properties, all with driveway and many with multiple vehicles parked on their driveways.
This is correct.
The northern end of the service road is less than 200m from a pair of roundabouts, that give easy access to trunkl roads in three directions, the A44 westbound to Worcester, the A46 eastbound to Oxford and the A46 northbound to Stratford.
I'm not sure how this is relevant? Penderyn is about 1.5m from the A465, which is the only road of significance in the area, and is likely to be the desired target for most residents for shopping, employment etc.
Add to that the speed limit there, - national speed limit (60mph) throughout the complex which drops to 40mph at the beginning of the A4184 southbound exit towards Evesham. The 40mph limit transitions to 30mph some 1.2km south of the junction.
Again, I'm not entirely sure how this is relevant. The A4059 is a mixture of 50 and 40 between the A465 and Penderyn.
So the through traffic, local traffic and cycles/pedestrian traffic conditions are completely different between the two examples that you attemped to equate.
Indeed. For the A4059, the annual average daily traffic (AADT) was a bit under 4500 in 2018 (there may be more recent data available, this is the latest figure I could find on
SABRE Maps). The A4184 is a bit under 11000 AADT in 2018.
As anyone who lives in the area will know, Evesham suffers from horrendous traffic problems at times. Plenty of traffic goes straight through the town, rather than round the bypass. Evesham also has plenty of local amenities, which are well within walking distance, so there should be a reasonable level of pedestrian activity.
Penderyn is a small village on a minor road that may well be used as a rat run when the Heads of the Valleys road and the A470 are congested.
So it might. And any drivers doing so
should be aware that the standard of the road is lower than the A465/A470, and adjust their driving accordingly. (I appreciate that many won't.)
(As an aside, "rat run" is a misnomer: unless specifically prohibited, all public highways are free to be used by anyone, whether they be a driver or pedestrian or cyclist (or horse rider etc). Therefore there is no reason why someone cannot use a particular road, just because the locals don't like it. Yes, in many cases the so-called "rat run" will not be suitable for use by many vehicles (and there are assorted reasons for this, of which likelihood of encountering pedestrians in just one. A weak bridge might be another reason). Yes, it may cause noise/air pollution. But that doesn't make it a "rat run", regardless of the popular terminology people might like to use. The only way to prevent people from using "roads not suitable for through traffic" is to stop it from being a through route (by installing a modal filter half way along, for example).)
The residents of that village need adequate protection from motorists who somehow see the village as irrelevant to their speed.
I hope you aren't accusing my previous post of stating this, because it doesn't.
The road at Evesham is a different kettle of fish, - a wealthy area wgere the majority of the population have one or more cars available to each household, so the pedestrian is unlikely to be at so much of a risk.
I struggle to see how the number of cars per household has an effect on risk a pedestrian. It might, however, have an affect on the number of pedestrians, which in turn will affect the overall risk of pedestrian/vehicle incident, but the individual risk to a pedestrian will be the same.
Maybe you should have found a more relevant comparison, - if it exists.
In my post, I very specifically said the
alignment and visibility are similar. At no point did I mention any of the various other factors which affect speed limits. Furthermore, at no point did I say that one road should have a different limit to the one it has at the moment, I was simply pointing out an inconsistency between two similar Welsh roads only 8 miles apart, with wildly different speed limits (I note that you have made no mention of the second Welsh road I linked, on the A4221 at Caehopkin).
Personally, I would suggest that a 30 limit is appropriate for the A4059 (as it has been), with suitable signage indicating hazards as and when they arise. Despite the long straight bit having an
alignment and
visibility suitable for higher (as evidenced by other examples from elsewhere in the country), it is relatively short before reaching sections at either end where a higher limit would not be appropriate (sharp bends, school etc). Combined with the additional noise/air pollution of vehicles accelerating for only a short distance, having a higher limit for a few hundred meters would be pointless and have a detrimental effect on the residents, and the benefit to drivers of a few seconds is essentially zero.
The stretch of 20mph through Penderyn is approximately 1.3 miles. At 30, this takes around 2 minutes 40s, at 20 this is just under 4 minutes. A significant difference.
Here is
another similar road, this time in Hope in the Peak District. In this particular case, I have just looked on Google Maps for a similar road (because the other ones I am personally familiar with would no doubt be dismissed as irrelevant). As before, I am not saying it has the right or wrong limit, merely providing it as an example of a similar (but not the same) road which readers can look at if they so wish. It has a 30 limit. There is a much narrower space between the "service road" and the main road. The nearest count point suggests 7000 AADT in 2018. There is a college and a sports club nearby, and a bit further along is a pre-school and a sharp S-bend. There is also a mini roundabout. It is in a rural area, it is a village, and at times the road will be used by drivers wanting to avoid delays on the A57 or A628.