PTP flashcards
PTP · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- MPO designation threshold
- Metropolitan planning organizations are required in urbanized areas with population above 50,000; urbanized areas above 200,000 are further designated transportation management areas with added requirements.
- Transportation management area
- A TMA is an urbanized area over 200,000 population; TMAs must run a congestion management process, certify their planning process, and make project-level conformity determinations.
- Long-range plan horizon
- Federal law requires the metropolitan transportation plan to cover at least a 20-year horizon and to be updated every four years in nonattainment areas, every five years otherwise.
- Fiscal constraint requirement
- Plans and TIPs may include only projects for which funding can reasonably be expected; revenue forecasts must be explicit and project costs shown in year-of-expenditure dollars.
- Section 4(f) protection
- Section 4(f) bars federal approval of a project using publicly owned parks, recreation areas, wildlife refuges, or historic sites unless no prudent alternative exists and impacts are minimized.
- NEPA document classes
- NEPA review yields an environmental impact statement for significant impacts, an environmental assessment leading to a finding of no significant impact, or a categorical exclusion for minor actions.
- TIP minimum coverage
- The transportation improvement program must cover at least four years, be updated at least every four years, and list projects prioritized and consistent with the long-range plan.
- Transportation conformity test
- In nonattainment areas, plans and TIPs must show conformity with the state implementation plan through a build/no-build emissions test and a fiscal budget test over the full horizon.
- Four-step travel demand model
- The classic sequence is trip generation, trip distribution, mode choice, and traffic assignment; output of each step becomes input to the next, often with feedback loops.
- Gravity model formula
- Trips between zones equal productions of origin i times attractions of destination j times a friction factor and adjustment factor, normalized by the sum across all destinations.
- Peak hour factor
- PHF equals peak hour volume divided by four times the busiest 15-minute volume in that hour; values near 1.0 indicate steady flow, lower values indicate peaking.
- K and D factors
- K is design hour volume as a percentage of AADT; D is the share of peak hour volume traveling in the heavier direction, used to size directional capacity.
- Sample size for proportions
- n equals z-squared times p times one minus p divided by e-squared; at 95 percent confidence with p of 0.5 and plus or minus 5 percent error, n is about 384.
- Buffer index definition
- Buffer index is the 95th percentile travel time minus the mean travel time, divided by the mean; it expresses the extra time travelers must add for reliability.
- GEH validation statistic
- GEH compares modeled and observed link volumes using the square root of twice the squared difference over the sum; values below 5 indicate acceptable fit.
- Travel demand elasticity
- Elasticity is the percent change in demand divided by the percent change in price, travel time, or another factor; values below one in magnitude are inelastic.
- Transportation control measures
- TCMs are strategies written into a state implementation plan to reduce mobile source emissions, such as transit expansion, ridesharing programs, and employer trip reduction rules.
- National performance measures
- Federal rules set measures for safety (PM1), infrastructure condition (PM2), and system performance, congestion, and CMAQ emissions (PM3); states and MPOs must set targets.
- Environmental justice executive order
- Executive Order 12898 requires agencies to identify disproportionately high and adverse health or environmental effects on minority and low-income populations and ensure meaningful involvement.
- Crash modification factor
- A CMF is the ratio of crashes after a treatment to crashes before it, with other factors held constant; expected crashes equal predicted crashes multiplied by the CMF.
- Vision Zero safe system
- Vision Zero treats traffic deaths as preventable and targets zero fatalities, using a safe system approach with lower speeds, forgiving roadsides, and redundant protection.
- SMART objective criteria
- Objectives should be specific, measurable, achievable, relevant, and time-bound, so that progress toward broader goals can be tracked and reported to decision makers.
- Complete Streets policy
- A Complete Streets policy directs routine design, construction, and operation of roadways to serve pedestrians, bicyclists, transit riders, and drivers of all ages and abilities.
- Congestion management process
- TMAs must operate a congestion management process that identifies congested facilities, evaluates management and operations strategies, and links results to the plan and TIP.
- Federal default match ratio
- Most federal-aid highway and transit capital grants provide an 80 percent federal share; Interstate construction reaches 90 percent, and some safety or air quality programs differ.
- Highway Trust Fund revenue
- The Highway Trust Fund is financed mainly by federal fuel excise taxes of 18.4 cents per gallon on gasoline and 24.4 cents on diesel, plus truck-related taxes.
- Congestion Mitigation Air Quality funds
- CMAQ funds support projects that reduce emissions in nonattainment and maintenance areas and are flexible between highway and transit eligible purposes.
- Net present value rule
- Future benefits and costs are discounted to year zero at an approved real rate; a positive net present value and a benefit-cost ratio above 1.0 justify the investment.
- Tax increment financing
- TIF captures the growth in property tax revenue above a frozen base year within a defined district and uses it to repay infrastructure or redevelopment bonds.
- Regression to the mean bias
- Sites chosen for treatment because of unusually high crash counts tend to improve anyway; sound evaluations use comparison groups or empirical Bayes correction.
- Transportation asset management plan
- A TAMP documents condition targets, risk, and life-cycle investment strategies for pavements and bridges; states must prepare one under federal asset management rules.
- Obligation authority
- Contract authority lets states commit federal funds, but annual obligation limitation, distributed as formula obligation authority, caps how much can actually be obligated each year.