guardrail design

[Sparticus17]

A guardrail is warranted in one of my roadways according to the highway geometric design guide of Alberta. I was wondering how far past the critical 5m embankment drop location (the starting of the guardrail) would I extend the guardrail up the roadway in a 60 km/h zone and if the roadway has heavy truck traffic.

Thanks for your help,

Rookie

 

[ACtrafficengr]

Can you flatten the embankment to 1 on 3 or flatter?

If not, check w/ the Alberta transportation department or ministry to see what standards they use.


There are times when all the world's asleep,
the questions run too deep
for such a simple man.
Won't you please, please tell me what we've learned
I know it sounds absurd,
but please tell me who I am.

--from The Logical Song, by Supertramp

 

[ngneer]

not directly related to your question, but it this area of U.S. "guardrail" has been relpaced with "guiderail." In these litigious states, we cannot give the impression that these structures guard against the vehicle exiting the roadway. The rails only guide vehicles to remain on the pavement. This change directly resulted from a lawsuit in which the highway agency was determined negligent by giving drivers the belief that the rail would work in all situtations, thus guardrail. Sorry to digress from your engineering question.

 

[ACtrafficengr]

ngneer - are you a fellow New Yorker?

There are times when all the world's asleep,
the questions run too deep
for such a simple man.
Won't you please, please tell me what we've learned
I know it sounds absurd,
but please tell me who I am.

--from The Logical Song, by Supertramp

 

[ngneer]

formerlyltapjim,

Not a new yorker, but close. I work in southeastern pa. I read a similar case during torts from washington state. The professor asked if any engineers were present, at which time I volunteered to submit to infamous socratic method. This attorney had been directly involved in litigation in which the issue "guardrail" versus "guiderail" was discussed. Sorry to digress once again.

 

[KRSServices]

Sparti,

Alberta here too. Which AT office is providing you with the direction? Most of their guidelines are available online. In addition to this, RTAC has some good recommendations and guidelines as well.



KRS Services

http://www.krs-services.com

 

[johnycanuck]

Sparticus

Working with Alberta Transportation we calculate the guardrail length of need using Traffic Control Standards pg I-14. I believe this is published by TAC.