has proven notoriously hard - in place structural *capacity* was noted in a TRB Consensus report to Congress a few years ago as being something we all need to work on (it seemed extremely odd as a recommendation sitting alongside high-level recommendations)
the chart is % poor, which is when the users notice the road, and also an indication of backlog, but not that useful to notice the impact of investments. It would be much better to have an indication of “remaining structural life” or a state-of-good-repair measure, but that… +
complexity from the pavement side, but also because 3R + projects typically are a good opportunity to update / replace all systems (safety, drainage, etc) so they take longer to even design, especially on existing facilities, and also to construct. So the higher ROI is preserve-first, but…
The point: pavement management principles tend to steer the manager toward prioritizing preservation vs tending to the worst roads (in this area we have collectively observed this in actual practice). Pavement preservation requires order of magnitude less engineering effort (in part because of… +
Just one point and one conjecture
First the conjecture - we may have been, in some cases, close to industry capacity in some construction areas particularly in road work (like paving) - it would be good to study this via bid analysis by work item, for instance, which is typically publicly available
At the end of the day, there is no easy fix for this.
Distress: 20/100
Function: 10/100
Difficulty of implementing a solution, now: 100/100
There is also the possibility, as is even mentioned in the 13 comments in the article, that there has been mire extreme weather and that this type of distress has shown up elsewhere in the Kent area - conditions outside the design parameters… +
I don’t know what happened here, but I do know enough of TRRL and people there and the work done there (prob TRL continues at least some of this tradition) to know that there is know-how to have handled a case like this at design.
… +
questioning before adopting a design, a lot of pressure. Pavement, usually relegated to other sexier considerations on projects, here takes center stage (or things can turn out badly.)… +
Fascinating* situation on so many levels. Swelling soils are, for pavement engineers, difficult both from a technical standpoint (the solutions are site-specific) and from a political POV: The solutions are almost invariably $$$$… so it’s a lit of internal… +
www.kentonline.co.uk/herne-bay/ne...
I’m cobbling one together😀
Stone dust, in this terminology, looks to be the same as screenings (that is just how I’ve learned to talk about it in my neck of the woods), I should have included both terms for clarity, so thank you (and for the illustration as well!)
sieve (4.75mm) and screenings are angular and well-graded, providing support for the riders and performance even in the rain.
Distress: 90 (I think I see remnants of a couple potholes on the left side not compacted or with more of the coarse chips)
Function: 100
Photo: 100
Subject (bike path): 110
In short, the relationship between the contact area of the bike tire with the ground. Aggregate that is larger than 3/8” tends to result in an uncomfortable ride (and complains to the road managers.)
I don’t have much more to say except they seem to have done it correctly here, mat’l passes #4…+
It could be related to Har-Tru or one of those tennis surfaces. But that is a short length and this Pathway is ar least 20 km long. Much harder to use a high-maintenance material like that, Yet for bicycles in particular ride comfort means the surface texture is important… +
Last weekend at Tanglewood (Lenox, MA) I had the pleasure of spending most of the morning and afternoon, and one of the paths (from the shed to Ozawa Hall) is surfaced with a very interesting material, sort of grey clay with some screenings. Really packed in nicely, smooth for walking or whlchr… +
In the meantime, here is a case study we did for the City of Milwaukee (Wisconsin) Comptroller in 2007-2008, following a similar set of conditions.
www.milwaukee.gov/ImageLibrary...
like this one.
I guess I have to do some organizing of thoughts here to write about how to a) avoid this state of affairs, and also b) how to move forward so you don’t repeat the same mistakes. The field is “pavement and asset management” and it’s my professional passion… +
In large part this is because users really “aren’t bothered by the road until they actually are:” For most of the deterioration trajectory the user experience is pretty much the same. I hate to use the term “tipping point” but there definitely is one, and it usually involves a bad press story… +
As we under-invest in pavements, the deteriorating state is appropriately expressed as “loss of slack in the system.” Then one day the whole thing appears to break almost at once. … +
There are many ways and threads to answer this, but I would like to focus on my observation of the *failure mode of a pavement network:*
when the entire network is painful for everyone to use, like in this example.
Why is that? Why do we look like “the sky is falling” types and then “how come these people didn’t see it coming?” when the (huge!) bills come due? … +
and they get press and all, but until next year everyone pretty much forgets about them (particularly at public budget times). Except… +
One of the hardest things to communicate for infrastructure managers everywhere is the backlog of needs of a network. We come out (ASCE in the US) with dire report cards… +
infrastructurereportcard.org/cat-item/roa...
Pavements typically don’t die- they become zombies - they keep on being there, they just become harder and harder to traverse and costly for you (in vehicle operating costs.). … +
Or, as the entire article hints at, the overall network has pretty much failed. That’s because generalized potholes are what a failed pavement looks like. … +
it is highly unlikely that paving contractors and inspectors all forgot how to pave over an entire region. So either you have road-manager and road-builder incompetence (in the country (UK) of Telford and MacAdam? unlikely) or you are seeing structural failure expressed in terminal distress… +
Potholes can be formed (as in the case of British Bigfoot, discussed in this account a couple of days ago) by deficiencies in the surface lift of a pavement. At the scale of a segment of road, the fix fot surface potholes is rather straightforward: “Mill and fill” the lift. But: … +
When the public is complaining about a generalized pothole problem, you likely have a massive backlog of pavement needs.
Citizen complaints express a tacit “minimum condition level” for pavements. Potholes everywhere are a symptom and cannot be addressed in a vacuum..+
www.bbc.com/news/article...
is in parking areas and lower-traffic streets and roads.
Here it looks in good, sound condition, even if I can see some aggregate without the asphalt coating, which can lead to early raveling (see previous post)
Distress: 85/100
Function: 90/100
Photo: 100/100