PTP cheat sheet

23 U.S.C. 134 and 135 establish the metropolitan and statewide planning processes; an MPO is required in each urbanized area over 50,000 population, and a Transportation Management Area is an urbanized area over 200,000.

The metropolitan transportation plan must cover at least a 20-year horizon and be updated every 4 years in nonattainment or traffic control measure areas, and every 5 years elsewhere.

The TIP covers at least 4 years, is updated at least every 4 years, must be consistent with the long-range plan, and must be fiscally constrained; the STIP is the statewide compilation of TIPs plus rural projects.

The UPWP is the annual budget and work program for MPO planning studies; it is adopted before the work is performed and is the vehicle for federal PL and 5303 planning funds.

Fiscal constraint means the plan and TIP may include only projects with reasonably available revenue, shown in year-of-expenditure dollars; unfunded projects may appear only on an illustrative list.

Conformity applies in nonattainment and maintenance areas and requires a build/no-build emissions test against the SIP motor vehicle emissions budget plus a fiscal budget test for each horizon year.

NEPA decision classes: EIS leading to a Record of Decision; EA leading to a FONSI; categorical exclusion for actions with no significant effect. Section 4(f) protects public parks, recreation areas, wildlife refuges, and historic sites.

Performance-based planning cycle: goals -> measurable objectives -> performance measures -> targets -> strategies and investments -> monitoring and reporting back to the plan.

Four-step model sequence: trip generation -> trip distribution -> mode choice -> traffic assignment; feedback loops return congested assignment times to distribution and mode choice.

Gravity model: T_ij = (P_i * A_j * F_ij * K_ij) / sum over j of (A_j * F_ij * K_ij), where F_ij is the friction factor and K_ij a socioeconomic adjustment factor.

Peak hour factor PHF = peak hour volume / (4 x highest 15-minute volume); HCM level of service is assigned from volume-to-capacity ratio and control delay, ranging LOS A through LOS F.

AADT = short-term count x seasonal adjustment factor x axle correction factor x day-of-week factor; continuous count stations are used to develop the adjustment factors.

K factor = design hour volume / AADT (commonly 0.08-0.12 urban); D factor = peak direction volume / total peak hour volume (commonly 0.50-0.60).

Minimum sample size for an estimated proportion: n = z^2 * p(1-p) / e^2, with z = 1.645 at 90 percent, 1.96 at 95 percent, and 2.576 at 99 percent confidence.

Reliability metrics: Buffer Index = (95th percentile travel time - mean travel time) / mean; Planning Time Index = 95th percentile travel time / free-flow travel time.

Model validation uses GEH = sqrt(2(M-C)^2 / (M+C)); GEH below 5 indicates good fit for an individual link, and at least 85 percent of links should meet that threshold.

Demand elasticity = percent change in quantity / percent change in price, travel time, or cost; capacity expansion lowers travel time and can induce additional travel.

Hierarchy of intent: goals are broad and aspirational, objectives are measurable, performance measures quantify progress, and targets are time-bound commitments adopted under 23 CFR 490.

National performance measures: PM1 covers fatalities and serious injuries per VMT; PM2 covers bridge and pavement condition; PM3 covers travel time reliability, peak hour excess delay, and CMAQ emissions.

States set performance targets within 1 year of a final rule, and MPOs must adopt targets, either the state's or their own, within 180 days of the state action.

Transportation conformity requires the plan and TIP to pass the build/no-build emissions test and the budget test for each regulated pollutant and each horizon year.

Executive Order 12898 and Title VI require analysis of disproportionately high and adverse effects on minority and low-income populations, plus meaningful involvement in decisions.

Expected crashes = predicted crashes x CMF1 x CMF2 x ...; crash reduction factor CRF = (1 - CMF) x 100 percent for a single countermeasure.

Safe System / Vision Zero assumes human error is inevitable and sets design and operating speeds below human injury tolerance, typically 20-30 mph where modes mix.

Transportation control measures adopted in the SIP must be implemented on schedule; delaying a TCM requires a new conformity determination before the plan or TIP can proceed.

Standard federal share is 80 percent for most NHPP, STBG, CMAQ, and transit capital grants; Interstate construction is 90 percent; some safety and air quality funds allow higher shares.

Federal motor fuel excise taxes are 18.4 cents per gallon on gasoline and 24.4 cents on diesel (unchanged since 1993); the Highway Trust Fund has needed general fund transfers since 2008.

Contract authority allows commitments, but annual obligation limitation caps what can actually be obligated; unobligated CMAQ funds lapse after 3 years and are redistributed.

Benefit-cost analysis: NPV = sum over t of (B_t - C_t) / (1+r)^t; USDOT guidance uses a 7 percent real discount rate for the base case, and B/C of 1.0 is the break-even rule.

Value capture tools include tax increment financing, special assessment districts, development impact fees, joint development of transit property, and air rights leasing.

Project delivery options include design-bid-build, design-build, construction manager/general contractor, and P3 concessions such as DBFOM; P3s transfer risk but carry a higher cost of capital.

Before-after safety evaluation must control for regression to the mean, volume changes, and reporting trends; empirical Bayes and comparison groups are standard corrections.

Asset management: states must prepare a risk-based Transportation Asset Management Plan covering pavements and bridges, with life-cycle investment strategies tied to condition targets.