The Pankian Metaphor 3079

my original comment-observation

included the observation: "and were never built for the number of buttociated heavy truck axle-loads (that are the result of the municipal bus traffic)"

the issue repeated in all of the road design references are designing to expected traffic volumes and available budget. the repeated references are that the consideration isn't to maximum load but to number of times axle-load ... above some threshold will be applied. the citation of included a dozen or so times from cal. state highway design ... talks about equivalent ESAL axle-loads ... and mentions converting number of lighter (fractional) axle-loads (above the threshold that results in deforming road construction material and therefor damage, wear&tear) into equivalnet ESAL axle-load damage

the referenced URLs road design documents are constantly referencing designing for expected traffic (i.e. accumulation of damage by repeated axle-loads) and budget. A previously posted DOT URL reference included comment about current traffic activity was frequently never aniticipated and so the volume of heavy truck axle-loads is severely shortening the projected 25year road lifetimes.

the article on accumulation of bus traffic damage on residential streats wasn't about the residential streets having been underdesigned ... but that they had been designed for expected projected traffic and within available budget (frequent phrase that seems to crop up in the road design references) .. aka it costs a lot more to build residential steets that have reasonable lifetimes when there is large accumulation of heavy truck (equivalent) axle-loads.

one of the points raised was trade-off with the high costs of building all residential streets for high accumulated heavy truck (equivalent) axle-loads (the result of bus traffic) ... even tho bus traffic is restricted to specific route ... versus the still significant cost of only building specific residential streets to handle heavy truck (equivalent) axle-load traffic (from buses) for a specific route. Supposedly one of the advantages of buses and roads ... versus trollys and tracks ... was that buses had significant freedom of changing routes compared to trollys and tracks (which would be lost with only building specific streets to handle damage from bus traffic).

aka ... the roads were purposefully underdesigned ... they had been designed for specific lifetime based on projected traffic (of heavy truck equivalent axle-loads, aka accumulation of damage the result of repeated axle-loads) and budget. During the expected road lifetime (that it had been designed for) ... things changed ... and therefor damage (from repeated heavy truck equivalent axle-loads) accumulated at greater than the origina projected rate.

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