As transportation agencies across the nation explore intelligent systems to improve traffic flow, accurate and real-time vehicle detection becomes paramount. Increasingly, DOTs are moving toward non-intrusive detection technologies due to their ease of installation, lower cost, and reduced maintenance requirements compared to traditional in-road sensors. In Utah, the Department of Transportation (UDOT) has taken a proactive step through the I-15 Coordinated Adaptive Ramp Metering (CARM) project. Among the 10 cutting-edge detection units evaluated, a combination of radars, cameras and LiDARs, the Houston Radar SpeedLane Pro—designated as Unit #10—demonstrated outstanding performance across all key metrics.
Rigorous Testing Under Real-World Conditions
The Test Bed was designed to stress-test detection technologies across a variety of challenging traffic conditions, including:
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Recurring PM congestion (35–45 mph)
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Moderate congestion (20–35 mph)
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Severe congestion (stop-and-go, <10 mph)
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Winter snow conditions
Each device was benchmarked against the CEOS TIRTL light-based detection system, widely accepted as a standard of accuracy in CARM applications. Metrics included vehicle speed, volume, and occupancy accuracy within ±2%, with an emphasis on real-time responsiveness.
Unmatched Accuracy Across Metrics
From recurring PM congestion to winter storms, Unit #10 consistently delivered superior accuracy in key performance areas:
- Volume Accuracy: The SpeedLane Pro was within the ±2% threshold for all-lane volume during nearly all daytime periods, consistently outperforming many peers, including other radar and LiDAR units:
“#10-Radar was shown to be the most accurate radar device within the recurring PM congestion scenario.” (Note: Radar #10 is Houston Radar SpeedLane Pro as identified to us privately by the agency.)
- Speed Measurement: While minor fluctuations (<3 mph) were observed compared to TIRTL, the overall speed data showed excellent consistency and reliability even during congestion and severe weather.
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Occupancy Consistency: The occupancy readings of Unit #10 were closely aligned with TIRTL data—falling within 3–5% variation even during the most congested periods. This is notable when other units showed 10–35% discrepancies.
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Winter Reliability: In the snow evaluation on February 13, 2025, the Houston Radar SpeedLane Pro was the most accurate device tested, with volume counts “consistently within 1 vehicle per 20 second bin” compared to manually verified CCTV footage.
A Cut Above the Rest
Compared to other high-performing units, the SpeedLane Pro offered greater stability across congestion levels and remarkable performance in winter conditions, where LiDAR and some video systems struggled or failed entirely. As the report emphasizes:
“The (…) and #10–Radar devices were the best performing overall and show potential to meet CARM standards pending additional coordination…”
“#10–Radar devices were the best performing overall and show potential to meet CARM standards pending additional coordination…”
“side-fire radar devices proved to be the best performing among all devices within the traffic performance metrics and congestion scenarios”
Conclusion:
Houston Radar’s SpeedLane Pro, evaluated as Unit #10, didn’t just meet expectations—it set a benchmark for what modern freeway detection technology can achieve. As UDOT looks to scale CARM operations, the SpeedLane Pro stands out as a reliable, high-performing, and future-ready solution.
The test report is available at https://houston-radar.com/wp-content/uploads/2025/07/UDOT_CARM_Detection_TestBed_Evaluation_2025July16-Email-1.pdf