How many US DOT are currently using AASHTO LRFD for bridge design?

[yjung]

I am wondering how many US DOT are currently using AASHTO LRFD code for their bridges.

Arizona = ASD
Washington = LRFD

I am not sure about other states. Can anyone tell me about it?

 

[rowe]

SCDOT = LRFD

 

[Qshake]

Kansas DOT - LRFD
IDOT - has been on the verge for years. Just never made it over the top.
MoDOT - LFD/ASD
PennDOT - LRFD

 

[rowe]

It's my understanding that AASHTO's current plan is to not issue any more editions of LFD (although interims are to continue until 2007 - I think). Therefore, it seems that most states will soon have to adopt LRFD or maintain their own LFD standard.

 

[koodi]

Rowe, what is this about LFD and LRFD, I thought they were the same thing. Load Factor Design = Load Resistance Factor Design?

 

[Qshake]

KOODI,

The concepts of load factors are similar, but with LRFD you also have resistance factors to apply for material behavior.

Definitely not the same thing.

 

[dbags]

ConnDOT = LRFD

 

[rowe]

To All,

Qshake is right. The concepts are similar. BUT, The AASHTO LRFD Guidelines are VASTLY different than LFD. I would suggest to all who are planning to continue in bridge design to invest in the latest LRFD manual. It's not an easy leap; it will require alot of reading beyond the "articles". Fortunately, the LFRD is written similar to the ACI in that there is a running commentary on the same page as the article (I found this very helpful).

The LFD code was written similar to ACI's (1.4DL + 1.7LL, etc.). The LRFD codes have incorporated specific bridge studies to incorporate bridge statistics (not buildings) with alot of consideration to areas not specifically addressed by the LFD (e.g. skewed bridges).

 

[bridgebuster]

NJDOT, FDoT, and WVDOT = LRFD

NYSDOT is heading towards LRFD

 

[TexasAggieCE]

TxDot = LFD/ASD - but looks like maybe a very (could be really slow) move to LRFD.

On a side note - I am working at getting my masters degree in structural engineering at night at the University of Houston. I took a bridge design course last spring and we were taught the LRFD code. I do believe that TxDot is beginning to look at what it might take to switch, but I could be wrong. TxDot has issued some standard bridge designs (for just a CIP slab bridge) using the LRFD code.