The memo is scope insurance — step 1 of Workflow - TIA from Request to Submittal. Everything the agency agrees to here, they can’t spring on you at review. Write it so a reviewer can approve with one read.
Tip
Get it signed off BEFORE counting. Counts collected before concurrence are money at risk — a reviewer who wants a different intersection, season, or peak owns your redo. A one-line email reply saying “concur” is enough; save it in the project file.
The skeleton
- Study purpose & project description — reviewer checks: does the land use/size/opening year here match the site plan and application on their desk?
- Study area & study intersections — reviewer checks: were intersections picked by a stated rule (agency trip/percentage threshold, distance) and not by convenience; any known problem locations quietly omitted?
- Count plan — reviewer checks: locations, count types (TMC/tube), day-of-week and school-in-session timing, peaks to be counted, seasonal adjustment source.
- Trip generation, with sources and caps — reviewer checks: ITE land-use codes and edition, independent variables, and that internal-capture/pass-by reductions are named UP FRONT with their caps (Trip Generation - Internal Capture and Pass-By) — reductions that first appear in the report get rejected.
- Distribution & assignment basis — reviewer checks: a stated basis (existing count patterns, model select-link, market/gravity logic) plus a draft arrow figure, not “engineering judgment” alone.
- Growth rate & horizon years — reviewer checks: growth source (historical counts, model, agency default), committed/background developments listed by name, and horizon years tied to phasing/buildout per their rules.
- Analysis tools & LOS standards — reviewer checks: software and method version (HCM edition, Synchro settings basis), queue-reporting source, and the adopted LOS/queue standards each scenario is judged against — written down so “failure” is unambiguous later.
- Agreed submittal contents — reviewer checks: scenarios, mitigation approach if standards fail, figures/appendices they expect (count sheets, LOS worksheets, signal warrants) — the table of contents you’re both signing up for.
Habits
- One page of text plus tables/figure is the target; a memo the reviewer can’t approve in one sitting invites a meeting.
- Steal accepted language from prior memos and the Wording Bank and Email Patterns; every accepted memo makes the next one start at 70%.
- Anything the agency changes → revise and recirculate the memo, don’t just “note it” — the memo is the contract of record.
Practice question: the agency’s reply concurs “except use 2% growth and add the CR 580 intersection” — what exactly do you send back, and what changes in your fee conversation? QA/QC reminder: the report’s methodology chapter must match the concurred memo word-for-word or explain every deviation — reviewers diff them.
See also: Workflow - TIA from Request to Submittal · Trip Generation - Internal Capture and Pass-By · Wording Bank and Email Patterns