Grid-Powered Emergency Vehicle Preemption & Transit Signal Priority (EVP/TSP) System

Overview

The RC-EVP-500 is a multi-mode Emergency Vehicle Preemption and Transit Signal Priority (EVP/TSP) system that gives emergency vehicles and public transit buses a clear green path through signalized intersections — cutting ambulance and fire-truck response times, improving bus schedule adherence, and reducing collision risk at controlled junctions. Designed to scale from a single arterial corridor to a metropolitan network of hundreds of intersections, the system integrates with existing NTCIP-compliant traffic signal controllers without requiring controller replacement or civil modifications. REDCOAST.LTD engineers every subsystem from the ground up — the OVU-300 onboard vehicle PCB, the IPC-200 intersection preemption controller, the OD-100 optical detector signal-processing board, and the PriorityNet™ cloud management platform — so every element of the signal chain is auditable, deeply customizable, and free of third-party black-box dependencies.

Key Features

• Triple-mode detection: GPS/4G-LTE cellular, 940 nm pulsed optical infrared (IR), and optional DSRC/C-V2X radio — operators configure the mix that matches their infrastructure and budget
• Sub-two-second actuation: GPS-path preemption request-to-controller output in under 2 seconds; optical path under 1 second from detector trigger — green is ready before the vehicle reaches the stop line
• 10-class priority hierarchy: distinguishes fire apparatus (Class 10, highest), ambulance, police, transit bus, utility and maintenance vehicles — simultaneous multi-vehicle requests resolved deterministically, highest class always wins
• NTCIP 1211-native IPC-200: interfaces directly with NEMA TS-2 and ATC 5201 signal controllers via serial or Ethernet; no controller swap, no rewiring, no civil work
• Selective conflict clearing: only conflicting approaches hold red; non-conflicting phases continue normally, minimising grid-wide delay disruption
• Predictive approach modelling: GPS path-ahead algorithm sends preemption requests 300–600 m before arrival, dynamically adjusting ETA as vehicle speed changes
• Fail-safe degradation: loss of cellular or optical link causes the intersection to revert to normal timed operation — no phase lock-up, no safety compromise
• Edge-local operation: IPC-200 stores intersection geometry and vehicle class maps locally; preemption can execute without cloud connectivity in degraded-network scenarios
• Fleet-wide real-time dashboard: dispatchers track every OVU on a live map with active preemption status per intersection, event logs, and response-time analytics

Technical Architecture

The RC-EVP-500 operates across three tiers. At the vehicle tier, each OVU-300 onboard unit — a custom four-layer PCB in an IP67 polymer housing — integrates a high-sensitivity GNSS receiver (GPS + GLONASS, CEP < 2.5 m), a 4G LTE Cat-1 cellular modem (with optional 5G NR upgrade), and a switchable 940 nm pulsed IR emitter. The OVU-300 draws from the vehicle's 12/24 VDC supply and streams encrypted position, heading, speed, and vehicle-class telemetry to both the cloud platform and nearby intersection controllers. When the vehicle enters a configurable geofence around a mapped intersection — default 600 m radius — the OVU-300 issues a signed preemption request packet containing vehicle ID, class, approach lane, and estimated time-to-stop-line.

At the intersection tier, the IPC-200 Intersection Preemption Controller mounts inside the existing traffic signal cabinet and connects to the native controller via NTCIP 1211 serial/IP interface plus a direct hardware preemption input. Up to four OD-100 mast-arm optical detectors per IPC-200 feed decoded IR pulse data through a purpose-built pulse-decode ASIC on the PCB, filtering out solar noise and distinguishing coded 940 nm emitter signatures at ranges up to 750 m. The IPC-200 arbitrates simultaneous priority requests by class, executes the preemption sequence (terminate current phase → establish conflict red → activate protected green → hold for configurable duration → restore normal operation), queues lower-priority requests, and logs every event to on-board non-volatile flash (30 days of local history). An embedded eSIM provides 4G LTE backhaul to the cloud platform and receives OTA firmware updates.

At the cloud tier, the PriorityNet™ SaaS platform provides a real-time map of all OVUs and active preemptions, schedule-adherence analytics for TSP-mode transit buses (cross-referenced against GTFS-RT feeds), after-action reports (seconds saved per run, intersection utilisation heat maps), and a REST API for integration with existing CAD/dispatch, AVL, and transit management systems. PriorityNet™ is available as cloud-hosted or on-premise deployments for agencies requiring data sovereignty.

Connectivity & Power

The IPC-200 connects to the traffic signal cabinet via RS-232/RS-485 serial or 100Base-T Ethernet depending on controller generation, and draws 120/240 VAC mains power directly from the existing cabinet supply — no additional power run is needed. OD-100 detectors connect to IPC-200 via shielded RS-485 twisted-pair cable along existing conduit runs. The OVU-300 onboard unit operates on 12/24 VDC vehicle power, consuming under 3 W at idle and under 8 W when the IR emitter is active. Cloud backhaul for IPC-200 uses an embedded multi-band eSIM (LTE 700/850/900/1800/1900/2100 MHz) covering over 190 countries; optional 5G NR Sub-6 GHz daughter-card reduces round-trip latency to under 20 ms for latency-sensitive deployments. The optional DSRC/C-V2X radio daughter-card (SAE J2945.1 / IEEE 802.11p or 3GPP Rel-16 C-V2X PC5) prepares intersections for connected-vehicle ecosystem integration. All cloud communications use TLS 1.3 with hardware PKI-backed device certificates.

Protection & Reliability

The OD-100 optical detector is housed in UV-stabilised polycarbonate rated IP66 and IK10, withstanding direct water jets, sand ingress, and minor vandal impacts. Both OD-100 and IPC-200 are rated for the full NEMA TS-2 environmental envelope: operating temperature −40 to +74 °C, 95% non-condensing humidity, and vibration per NEMA TS-2 Section 2. The IPC-200 PCB is fully conformally coated and tested to IEC 60068-2-1/2/6/14 for thermal shock, damp heat, sinusoidal vibration, and thermal cycling. The OVU-300 meets IP67 (fully sealed, immersion-rated for in-vehicle installation) and operates from −40 to +70 °C. IPC-200 MTBF target is > 80,000 hours. A hardware watchdog on every unit triggers autonomous reboot on firmware fault within 30 seconds, with automatic safe-state output ensuring the intersection defaults to timed operation during recovery.

Application Scenarios

Urban Emergency Medical Corridor: A city equips its EMS fleet with OVU-300 and deploys IPC-200 at signalized intersections along the primary hospital access arterial. Ambulances receive green phases at each equipped intersection, reducing average per-intersection delay from 18 seconds to near zero and cutting end-to-end response times by 1.5–2.5 minutes — critical for cardiac and stroke calls where outcome correlates directly with arrival speed.

Bus Rapid Transit (BRT) Schedule Recovery: A transit authority operating mixed-traffic BRT lines enables TSP mode for articulated buses. PriorityNet™ cross-references GTFS-RT schedule data and only triggers green extension or early-green when a bus is delayed beyond a configurable threshold — preserving general traffic performance when buses are on schedule, and recovering schedule adherence without dedicated infrastructure.

Airport Landside Emergency Access: An international airport deploys IPC-200 at key airside gate intersections and equips fire tenders and medical response units with OVU-300 at Class 10 (highest) priority. Emergency vehicles gain immediate corridor clearance from the fire station to any terminal gate, meeting ICAO CAT-1 airport rescue response-time targets without dedicated segregated roadways.

Multi-agency Metropolitan Network: A metropolitan TMC deploys a city-wide installation spanning police, fire, EMS, and public transit in one unified PriorityNet™ instance. Priority classes are assigned per agency and vehicle type; the REST API feeds live event data into the TMC's existing C2 dashboard, and the GTFS-RT integration gives transit operations a real-time view of bus delay recovery.

University and Hospital Campus Roads: A large academic medical centre deploys IPC-200 at campus internal intersections and equips security patrol, medical transport shuttles, and emergency response units. The lightweight campus-scale deployment delivers full preemption performance at a fraction of city-scale project cost.

Industrial Port and Logistics Hub: A major container port equips fire engines and emergency response vehicles with OVU-300 and deploys IPC-200 at high-risk junctions between pedestrian zones and heavy freight lanes. Controlled preemption provides a clear path for emergency vehicles without halting port operations beyond the minimum necessary conflict clearance.

Case-style Examples

Emergency Response Time Reduction on a Major Arterial: A city EMS department identified that ambulances were losing 12–18 seconds at each of 14 signalized intersections along the hospital corridor, accumulating over 3 minutes of delay per run. After deploying RC-EVP-500 with GPS/cellular preemption at all 14 intersections and equipping 32 ambulances with OVU-300 (no controller replacements, no civil works), the department recorded an average of 2.3 minutes saved per hospital-bound run in the first six months. The optical IR fallback layer ensured preemption continuity during periods of peak cellular congestion.

BRT On-time Performance Recovery: A transit authority operating a 16 km BRT corridor was recording 24% late-arrival rate at terminus due to signal cycle conflicts. Deploying RC-EVP-500 in TSP mode at 22 intersections and connecting PriorityNet™ to the agency's GTFS-RT feed improved on-time performance to 91% within three months. General traffic delay at equipped intersections increased by an average of 3.8 seconds per cycle — within acceptable tolerance per the agency's level-of-service policy — and the city avoided the capital cost of a dedicated BRT guideway.

Tiered Priority at a Campus Medical Network: A hospital system covering a 4 km² combined campus deployed 26 IPC-200 controllers, assigning medical transport shuttles TSP Class 5 and emergency first-responders EVP Class 9. The tiered hierarchy guaranteed that a true emergency would always supersede a late-running shuttle request. Integration of the PriorityNet™ REST API with the campus security camera VMS provided time-synced video clips for every preemption event, simplifying incident review and liability documentation.

Customization & Selection Guide

• GPS/Cellular only: lowest installation cost, no mast-arm hardware; best for new deployments where conduit access is limited. Typical actuation latency ~1.5–2 s. Requires reliable 4G coverage at each intersection.
• Optical IR only: retrofit-compatible with fleets already carrying coded IR emitters; IPC-200 replaces older discriminator hardware without changing vehicle units. Sub-1-second actuation; performance degrades in heavy fog (>200 m visibility impairment).
• Hybrid GPS + Optical (recommended): GPS handles advance geofenced requests and provides backup; optical provides fastest final-approach actuation and lowest stop-line latency. Highest reliability across weather and network conditions.
• DSRC/C-V2X add-on: for cities investing in V2I/V2X infrastructure; IPC-200 DSRC/C-V2X daughter-card enables interoperability with future connected-vehicle fleets and V2X RSU ecosystems.
• EVP-only vs. combined EVP+TSP: agencies needing only emergency preemption can deploy IPC-200 in EVP-only mode (lower licence tier); adding TSP unlocks GTFS-RT integration, schedule-based conditional priority, and bus delay analytics.
• On-premise vs. cloud platform: cloud SaaS is fastest to deploy; on-premise PriorityNet™ server suits agencies with data-sovereignty mandates or restricted-network environments (e.g., government or defence campuses).

Deployment & After-sales

IPC-200 installation inside a standard NEMA TS-2 or ATC cabinet takes under 2 hours per intersection — DIN-rail mount, terminal-strip wiring, no controller swap. OD-100 detectors affix to existing mast arms with a single stainless-steel U-bolt bracket; wiring routes through existing conduit to the cabinet. OVU-300 installs on a vehicle dashboard or A-pillar in under 45 minutes with supplied mount and OBD/power harness; no CAN-bus or ECU integration is required. REDCOAST.LTD ships IPC-200 units pre-configured with intersection GPS coordinates and phase maps, minimising on-site commissioning time. Typical project delivery for 20–50 intersections (hardware, platform, commissioning) runs 8–14 weeks from purchase order. PriorityNet™ includes 24/7 automated device health monitoring with email/SMS alerting on device fault. REDCOAST.LTD provides a 24-month hardware warranty on all units, with optional managed-service SLA covering remote diagnostics and on-site corrective maintenance within 48 hours for critical-path contracts.

Standards & Compliance

• NTCIP 1211 (Signal Control Priority — EVP/TSP messaging standard)
• NEMA TS-2 and ATC 5201 (traffic signal controller compatibility)
• FHWA MUTCD Section 4D (intersection preemption requirements)
• IEC 60068-2-1/2/6/14 (environmental testing: thermal, humidity, vibration)
• IP66 / IP67 (IEC 60529 enclosure ingress protection)
• IK10 (IEC 62262 impact resistance — OD-100 detector)
• SAE J2945.1 / IEEE 802.11p / 3GPP Rel-16 C-V2X PC5 (optional V2X radio)
• GTFS-RT (General Transit Feed Specification Realtime — TSP data integration)
• CE marking / RoHS 2 (EU market)
• FCC Part 15B (North America RF emissions)
• AES-256 + TLS 1.3 (cybersecurity — all over-air and cloud communications)

Why REDCOAST.LTD

Most EVP/TSP vendors supply closed, OEM-sourced hardware that locks agencies into proprietary emitter-detector pairs and firmware update cycles outside their control. REDCOAST.LTD designs and manufactures every PCB in the RC-EVP-500 system in-house — from the OVU-300 vehicle unit's GNSS/cellular board, to the IPC-200 intersection controller's NTCIP interface and pulse-decode ASIC circuit, to the OD-100 detector's signal-processing front-end. This full hardware ownership means priority class definitions, preemption timing parameters, encryption key management, and detector sensitivity thresholds can all be adjusted for local regulatory requirements or agency operating procedures — at the board level, not through a constrained configuration GUI. When a national road authority needs a custom vehicle class for military convoy priority, or a hospital network needs NTCIP 1211 extended with proprietary message fields for its CAD integration, REDCOAST.LTD engineers it into the firmware and PCB without a change-order from an upstream OEM. Every project is delivered as a complete integrated package: hardware, edge firmware, cloud platform, mobile dispatcher app, API documentation, and post-deployment technical support from a single team. Reach out to REDCOAST.LTD with your intersection count, fleet composition, and integration requirements — we will produce a project-specific configuration, BOM, and commissioning plan.