The brief
The highway authority required an Smart corridor that could warn drivers of fog, wrong-way vehicles, and incidents in real time — without relying on driver attention or mobile connectivity, and without tearing up existing signal infrastructure.
The challenge
- Dense fog events reducing visibility below 50 m for weeks at a time
- Wrong-way driving incidents on entry/exit ramps
- No existing V2I infrastructure on the corridor
- Mixed traffic: connected and non-connected vehicles
- Tight authority mandate: zero civil works, zero road closures
What we deployed
- 18 Spondit V2I RSUs dropped into existing signal cabinets across 42 km
- 42 km of continuous C-V2X coverage, plug-and-play with the existing adaptive-signal controllers
- Integrated Weather and AQ nodes at each RSU location for real-time visibility data
- Road Safety and Surveillance — wrong-way detection, speed enforcement, accident detection
- Navigation app integration for non-connected vehicles
- Deployment timeline: 5 months end-to-end
The solution architecture
Each RSU site pairs a Spondit V2I roadside unit with a co-located weather and air-quality node. Because Spondit speaks the existing cabinet protocol, every install was a drop-in — no new poles, no new trenching, no corridor closure. Visibility readings feed directly into the V2I advisory engine. When visibility drops below thresholds, the RSU broadcasts fog advisories to every connected vehicle within 300 m over C-V2X PC5.
For non-connected vehicles, the same advisories propagate to consumer navigation apps via the Spondbyte public event stream. Variable message signs at critical points display human-readable warnings. The entire corridor reports to a central monitoring dashboard accessible to the highway authority's control room.
Results
12
Fog incidents prevented
8
Wrong-way interceptions
180 ms
Avg V2I latency
99.6%
Corridor uptime
Quote
"Spondit dropped straight into our existing signal cabinets. We never closed a lane, we never repaved a shoulder. The fog advisories started working on the first morning after commissioning."
— Corridor Director, NHAI
Timeline
| Phase | Duration | Scope |
|---|---|---|
| Corridor survey | 2 weeks | RF planning, site identification, power audit |
| Cabinet prep | 3 weeks | Power feeds, fibre termination, backhaul |
| RSU deployment | 4 weeks | Drop-in install, antenna alignment, commissioning |
| Integration and testing | 6 weeks | V2I end-to-end, fog scenario testing, app integration |
| Go-live | 1 week | Phased corridor activation |
What's next
Extension to additional kilometres. Green Channel signal synchronisation for the urban approach sections. Emergency vehicle preemption integration with state police and ambulance services.