Proposed features/Access restriction axlecount
|Key:access; new routing restriction Key, axlecount=*|
|Status:||Draft (under way)|
|Applies to:||node; way; area; relation|
|Definition:||For describing vehicle access restrictions by the number of axles on the vehicle.|
This proposal arises directly from needing to include in OSM for a particular small bridge the conditions of a sign associated with the bridge, reading "No trucks over 2 axles except for local service".
I have done a reasonably thorough search of the wiki and not found mention of a proposal which would make this one redundant. I have also looked in OSMDoc for instances where people have added ad hoc axle number values — and have found no such instances. I have not done a search of the e-mail archives.
Many states in the United States have consistent or similar laws governing trucks in order to facilitate interstate truck transport of goods; therefore, I'm considering what I find in Delaware documents to be reasonably consistent with what I would find by investigating other states of the United States.
Bridge rating specifications
As related to trucks, a bridge's capacity depends not only upon the gross weight, but also upon the number and spacing of the axles and the distribution of load between the axles. Since it is not practical to rate a bridge for the countless axle configurations, Delaware's highway bridges are rated for six standard vehicles which are representative of actual vehicles on the highways. (Section 4.6)
The standards are presented in diagrammatic form showing number and spacing of axles and per-axle load.
Local road truck restrictions
In a presentation in August 2006 (archive.org), the US 301 Toll Diversion Working Group had a slide from a Breakout Session addressing the concerns of local communities regarding changes in truck traffic. Quoting from the presentation:
The evaluation and implementation of additional truck restrictions on local roads ... which may qualify for axle-based restrictions is recommended. (Slide 13)
The slide contains two possible sign layouts which communicate the message "No trucks over four axles except local deliveries". This seems to be very closely related to the sign observation which prompted this proposal.
It is common in the United States to have different levied tolls along toll roads depending upon how many axles a vehicle has. The following is a quotation from a Nov 2005 report to the Governor of Delaware on transportation development and funding (WebCite archive):
Effective October 1, 2005, toll rates on the Delaware Turnpike were increased from $2.00 to $3.00 for two-axle vehicles and from $6.25 to $10.00 for six-axle vehicles. The Turnpike toll structure includes a discount plan for commercial vehicles (with 3 or more axles) with EZ Pass,... (document page 9; PDF page 13)