This is a quick post to explain a simple (or not so simple) answer for what preliminary engineering actually means in the context of the local programs process.
Preliminary Engineering actually consists of two separate and distinct phases of work.
- Preliminary Engineering-NEPA. This phase consists of all the work that is necessary in order to get all the information for your NEPA (National Environmental Protection Act). You (meaning your engineering consultant, who must be TDOT pre-qualified and selected through the Federal consultant selection process) can do ONLY the level of survey and design work that is needed to complete your NEPA document, AND NO MORE.The next question would be, how much design and engineering work is that? The answer is whatever the TDOT Environmental Division tells you it is for your project. In general, this will equate to enough engineering design so that you have a reasonable picture of the impact your project will have on the surrounding environment. What it takes to get a NEPA document is a whole other post, and a process that changes regularly. Hint: You had better talk with Joe Matlock of TDOT to be sure.
Yes, I know for most local programs projects there is little of any “dirt being moved” (resurfacing, traffic signals, ect). It does not matter, it still needs a NEPA document approved by TDOT.
- Preliminary Engineering-Final Design. Once you have an approved NEPA document, AND NOT BEFORE, then you can start work on the “Final Design plans”. These are the actual design plans that you are more familiar with. This is the set of plans that will be turned in to the local programs office for review by TDOT Design.
Remember that each of these phases of work are separate, and you cannot have one before the other. If you are expecting to be reimbursed for these phases of work, you had better have a Notice to Proceed in hand from your local programs planner.
Now at one time you could work on both the design plans and the NEPA document at the same time. What changed? Well here is the story that I was told. On bigger Department of Transportation (TDOT, MDOT, GDOT, ect) they would work on both, have the plans completed, then they would get the NEPA document back and it turns out that based off the NEPA document they would have to change the plans. So guess what, now you would have to design your plans twice. Evidently the FHWA got sick of paying for the same thing twice, so they put the brakes on things so that now PE is divided into the two distinct phases.