Justifying AV Taxi Infrastructure
Given a deployment scenario (city district, fleet size, service area), produce a parameter justification covering five domains:
- Curb & pickup/dropoff (PUDO) zones — count, spacing, dimensions
- Road/lane markings & signage legibility for sensor perception
- Charging/depot infrastructure — stall count, power capacity
- V2X / connectivity coverage — latency and redundancy requirements
- Operational Design Domain (ODD) boundary infrastructure — geofencing support, weather/lighting thresholds
For each parameter: state the recommended value, the driving constraint, and the calculation method. Never present a number without its derivation.
Example snippet:
PUDO zone spacing: 300–400 m in dense CBD areas. Driving constraint: average pedestrian walking tolerance (≤5 min / ~400m per FHWA ped studies) balanced against curb space scarcity. Calculation: service area (km²) × trip density (trips/km²/hr) → required PUDO throughput → zones = throughput / (avg dwell time⁻¹ × curb slots per zone).
Progress:
- Step 1: Define deployment context (ODD, fleet size, demand density, climate)
- Step 2: Derive curb/PUDO infrastructure parameters
- Step 3: Derive perception-infrastructure requirements (markings, signage, lighting)
- Step 4: Derive energy/depot infrastructure parameters
- Step 5: Derive connectivity/V2X parameters
- Step 6: Cross-check parameters against regulatory precedent (e.g., CPUC, NHTSA AV STEP, city AV pilot ordinances)
- Step 7: Package as justification document with sensitivity notes
Step 1: Define Deployment Context
Collect/assume: service area size (km²), expected fleet size, trip density, street typology mix (arterial/collector/local), climate/weather profile, existing transit/curb regulation.
Step 2: Curb & PUDO Zones
- Zone count = peak-hour trip volume / (zone throughput capacity)
- Zone throughput = 3600s / (avg dwell time per vehicle, typically 30–90s)
- Spacing derived from walkability standards (~250–400m urban, up to 800m suburban)
- Dimensions: minimum 6.5m length per AV stall (accounts for conservative approach/departure buffers vs. 6m for human-driven)
Step 3: Perception Infrastructure
- Lane marking retroreflectivity: ≥130 mcd/lux/m² (above MUTCD minimum of 100) to ensure camera/LiDAR redundant detection in rain/low light
- Signage: standardized font/placement height consistency within ±10cm of MUTCD spec — AV perception models trained on standard geometry degrade with outliers
- Lighting: minimum 10 lux at crosswalks/intersections for camera sensor performance in low-light ODD
Step 4: Charging/Depot
- Stall count = fleet size × (avg daily charge time / operational hours) × utilization buffer (1.2–1.3x)
- Power capacity (kW) = stall count × charger power rating × simultaneity factor (0.6–0.8 for staggered charging)
- Depot siting: ≤15 min deadhead from service area centroid to minimize non-revenue miles
Step 5: Connectivity/V2X
- Latency budget: ≤100ms round-trip for teleoperation fallback; ≤20ms for safety-critical V2I (signal phase/timing)
- Coverage redundancy: dual-carrier or 5G + C-V2X overlap in ≥95% of ODD area
- Teleoperation bandwidth: ≥10 Mbps uplink per concurrent assisted vehicle
Step 6: Regulatory Cross-Check
Validate against precedent frameworks (CPUC AV deployment decisions, SAE J3016 ODD taxonomy, local DOT curb management pilots). Flag any parameter deviating >20% from precedent and justify explicitly.
Step 7: Package
Deliver as a table: Parameter | Recommended Value | Constraint | Derivation | Sensitivity/Risk.
Example 1: Input: "Робо-такси сервис в центральном деловом районе площадью 8 км², пиковый спрос 1200 поездок/час, флот 150 машин."
Output:
Параметр: Количество зон PUDO
Значение: 24 зоны
Ограничение: пропускная способность одной зоны при среднем времени посадки 60с = 60 поездок/час
Расчёт: 1200 поездок/час / 60 поездок/час на зону = 20 зон, +20% буфер на неравномерность спроса = 24 зоны
Риск: при росте спроса >15% потребуется пересмотр
Параметр: Разметка полос (ретроотражательность)
Значение: ≥130 mcd/lux/m²
Ограничение: устойчивое распознавание камерами/LiDAR в дождь и сумерках
Расчёт: базируется на MUTCD минимуме 100 + 30% запас для AV-сенсорной деградации
Параметр: Зарядная инфраструктура
Значение: 45 зарядных стойл, 2.4 МВт пиковая мощность
Расчёт: 150 машин × (4ч зарядки / 20ч операционных) × 1.25 буфер = 37.5 → 45 стойл с запасом;
мощность = 45 × 75кВт × 0.7 коэффициент одновременности ≈ 2.4 МВт
Example 2: Input: "Пригородный маршрут, низкая плотность, зимний климат."
Output:
Параметр: Расстояние между зонами PUDO
Значение: 600-800 м
Ограничение: низкая плотность спроса не оправдывает частые зоны; приемлемо увеличение пешей доступности
Параметр: Минимальная освещённость перекрёстков
Значение: 15 люкс (выше городского стандарта в 10 люкс)
Ограничение: снежный покров снижает контраст для камерных сенсоров, требуется компенсация
Параметр: V2X резервирование
Значение: dual-carrier покрытие обязательно (не 95%, а 100% ODD)
Ограничение: сельская/пригородная зона имеет меньше вышек — выше риск потери связи при телеоперации
- Always tie a number to a named constraint (physical, regulatory, or demand-based) — never present "industry standard" without the underlying study/spec.
- Build in buffers (15–30%) for demand variability and sensor degradation in adverse weather; state the buffer explicitly, don't hide it in the headline number.
- Use ranges, not single points, when the underlying context (climate, density) is variable — collapse to a point value only once context is fixed.
- Reference recognized frameworks (SAE J3016, MUTCD, NHTSA, CPUC) as anchors — this strengthens justification credibility to regulators.
- Separate "hard constraints" (physics, safety) from "soft constraints" (cost optimization, UX) in the final deliverable.
- Don't copy human-driven-vehicle infrastructure specs unchanged — AV sensor requirements (lighting, marking contrast, geometry consistency) are stricter.
- Don't ignore weather/lighting ODD boundaries — infrastructure adequate in clear daylight may be insufficient and must trigger service suspension zones, not be "worked around."
- Don't size depot/charging only for average demand — peak-hour and charge-cycle overlap drive real capacity needs.
- Don't treat connectivity as binary (covered/not covered) — latency and bandwidth thresholds differ by use case (safety-critical V2I vs. teleoperation vs. fleet telemetry).
- Don't omit sensitivity analysis — parameters derived from assumed demand/fleet size should state how much the recommendation shifts if inputs change ±20%.