CSS-Transit cheat sheet

Service frequency f and headway h are reciprocals: h (minutes) = 60 / f (trains or buses per hour); a 12-minute headway equals 5 departures per hour.

Fleet requirement N = ceil(cycle time / headway) + spare ratio; cycle time = running time both directions + layover/recovery time at each terminal.

Recovery time is typically set at 10-20% of one-way running time to absorb delay and preserve on-time performance.

On-time performance is usually measured against a schedule window (e.g., 0 to +5 minutes at timepoints); early departures are counted as failures at most agencies.

Transit capacity is a product of vehicle capacity and frequency: line capacity = vehicles per hour x crush or design capacity per vehicle.

Demand is peak-directional; load factor = passenger boardings / seats offered, and peak load point (not average) drives vehicle assignment.

Deadheading and pull-in/pull-out time count toward vehicle hours but not revenue miles; cost per revenue hour excludes non-revenue movement.

Schedule adherence depends on dwell time, which rises with boarding/alighting volume and fare payment method (off-board validation reduces dwell).

Route design tradeoffs: stop spacing of roughly 400 m (local) to 800-1,600 m (express/BRT) trades access for speed; closer spacing raises access but lowers average speed.

Safety Management Systems (SMS) rest on four pillars: Safety Policy, Safety Risk Management, Safety Assurance, and Safety Promotion.

Hazard vs. risk: a hazard is a condition with potential for harm; risk = severity x likelihood (or probability x consequence) and is ranked on a matrix before controls.

Control hierarchy, most to least effective: elimination, substitution, engineering controls, administrative controls/procedures, then personal protective equipment.

Safety assurance uses leading indicators (hazard reports, near misses, training completion) and lagging indicators (collision rate, injury rate, fatalities per 100 million vehicle miles).

FTA requires an Agency Safety Plan (ASP) with a Safety Committee (or equivalent) and annual review; the plan must be updated and certified per 49 CFR Part 673.

Security differs from safety: security addresses intentional acts (theft, assault, terrorism); countermeasures include CPTED design, lighting, CCTV, and emergency call boxes.

Incident investigation sequence: secure the scene, preserve evidence, interview witnesses, determine causal and contributing factors, then issue corrective actions with owners and due dates.

Emergency preparedness follows the phases: mitigation, preparedness, response, and recovery; exercises progress from tabletop to functional to full-scale drills.

Fatigue and hours-of-service controls, drug and alcohol testing programs, and post-incident testing are standard elements of a transit safety program.

FTA Circular 4220.1 governs third-party contracting; procurement methods include sealed bids (formal advertising, price-driven), competitive proposals (technical merit), and sole source (justified noncompetitive).

Micro-purchases (currently $10,000 threshold, adjusted periodically) need no competitive quotes; simplified acquisition and small purchase thresholds follow federal acquisition regulation updates.

Buy America requires rolling stock final assembly in the U.S. plus domestic content thresholds (currently 70% for rolling stock, rising over time) and a domestic steel/iron component.

Disadvantaged Business Enterprise (DBE) program (49 CFR Part 26) sets an overall goal with race-neutral and race-conscious measures; recipients must monitor prompt payment and goal attainment.

ADA complementary paratransit must be provided within 3/4 mile of fixed routes, same days and hours, and comparable response time; trip denial standards are defined in 49 CFR Part 37.

Title VI of the Civil Rights Act requires language access (LEP) and an equity analysis of fare and service changes with disparate impact review.

NEPA/CEQA environmental review: Categorical Exclusion, Environmental Assessment (possible Finding of No Significant Impact), or Environmental Impact Statement.

Procurement ethics: no conflicts of interest, sealed bids opened publicly, protests handled through documented procedures, and cost/price analysis required for negotiated contracts.

Bus testing: FTA requires testing at the Altoona Bus Research and Testing Center (model bus testing) before a new bus model can be purchased with federal funds.

Intelligent Transportation Systems (ITS) architecture layers: field devices (AVL, APC, signal priority), communications, back-office (CAD/AVL), and customer information channels.

CAD/AVL tracks vehicle location in real time; APC (automatic passenger counters) supplies ridership by stop for planning and NTD reporting.

Transit Signal Priority (TSP) requests extended green or early green at intersections; conditional TSP limits requests to late vehicles to protect cross-street traffic.

Fare systems: closed-loop (agency-issued card) vs. open-loop (contactless bank card/mobile wallet, e.g., EMV); account-based systems centralize fare rules and capping.

GTFS is the static schedule/data spec (stops, routes, trips, stop_times); GTFS-Realtime streams trip updates, vehicle positions, and service alerts.

Cybersecurity: apply defense in depth, network segmentation between operational technology (OT) and IT, patch management, and multi-factor authentication; TSA security directives apply to certain transit agencies.

Data quality rules: validate GTFS with canonical validators, monitor AVL feed uptime, and reconcile APC counts against farebox taps.

Predictive maintenance uses vehicle telematics (fault codes, brake and engine sensor data) to schedule work before failures, reducing road calls.

Battery-electric buses require depot charging analysis: route energy consumption (kWh/mi), charge time, block feasibility, and grid capacity upgrades.

Workforce planning formula: operators needed = (annual vehicle service hours x 1 / average annual paid hours per operator) + absenteeism/training coverage factor.

Absenteeism and spare ratio drive extra-board size; a common planning assumption is 10-20% coverage above scheduled requirements.

Labor relations: collective bargaining agreements set work rules, seniority-based pick of runs, overtime distribution, and grievance procedures.

Training standards: new operators typically complete classroom plus behind-the-wheel hours with a certified instructor before solo service; recurrent training is annual.

Succession planning maps retirements and attrition against critical roles (operators, mechanics, dispatchers) and builds internal pipelines.

Leadership competencies in transit: safety culture, data-informed decision making, stakeholder and board communication, and change management.

Key performance indicators for workforce: turnover rate, absenteeism rate, training completion, time-to-fill vacancies, and preventable collision rate per operator.

Professional development pathways include transit agency internal academies, APTA and state association training, and certifications in safety, maintenance, and operations management.

Diversity, equity, and inclusion efforts connect to Title VI obligations, workforce representation goals, and community engagement practices.