Signal Controllers, Central Management and Roadside Networks
Traffic Signal and Central System Security Testing
Signal controllers answer to a central traffic management system over fiber, cellular modems and wireless links built to keep traffic moving, not to resist an attacker. GDF tests the paths into that system, from the internet and agency network to the cabinet and the connected vehicle roadside unit. Agencies get findings ranked by public safety consequence and fixes sized for a capital program.
Scope the signal system
Scope by Corridor, Device Family and Management Path
A traffic engineer usually knows which corridors matter most; what is less clear is how many ways there are to reach the controllers on them. We scope by corridor and device family, signal controllers, detection, message signs, roadside units and the central traffic management system, and by every path that manages them, including vendor cloud services, maintenance laptops and the cellular modems added one project at a time.
Signal Controllers and Cabinets
Controllers, conflict monitors, detection and preemption equipment, cabinet switches and modems, and the local interfaces technicians use in the field.
Central Management and Field Networks
The central traffic management system, its servers and operator workstations, the fiber, cellular and wireless field networks, and the agency and vendor connections into them.
Connected Vehicle Roadside Units
Roadside units, their management interfaces, the signal phase and timing data they broadcast, and the certificate and update services they depend on.
Methodology
Testing Sequence for Signal Systems
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Exposure: Internet and Agency Network
We look for controllers, modems, cameras and management services reachable from the internet, then test what an attacker on the agency network or a contractor's laptop could reach.
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NTCIP: Device Management Protocols
We examine how central software and field laptops talk to devices, including NTCIP over SNMP, community strings and credentials, and whether a device accepts timing or configuration changes from a source it should not trust.
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Roadside: Cabinet and Wireless Access
In a test cabinet or one taken out of service, we examine local ports, switches, modems and wireless links, the access someone standing at the roadside would have.
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Bench Proof: Changes Off the Street
Changes to timing or device state are proven on bench equipment or a lab replica configured like production, or in a window your traffic engineer approves with a fallback plan in place.
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Corrections: Priorities and Retest
Each finding names the device, the path, the public safety consequence and the fix, prioritized against your maintenance and capital plans, and we retest after correction.
List the corridors and device families that concern you and we will propose where testing should start.
Testing Grounded in the NTCIP Device Standards
Traffic devices in the United States are commonly managed through the National Transportation Communications for ITS Protocol (NTCIP) standards, developed jointly by AASHTO, ITE and NEMA, which define the objects central software uses to read and change device settings. Earlier versions of the signal controller standard supported SNMPv1, which sends its community strings in clear text, and the proposed NTCIP 1202 v04 Actuated Signal Control standard, still in balloting, uses SNMPv3 and drops SNMPv1. That transition is a practical moment to test what your installed devices accept, and from whom.
Connected vehicle deployments add roadside units that broadcast signal phase and timing to vehicles and rely on certificates and remote management, so we test them both as network devices and as safety messaging equipment tied to the controller.
If a corridor upgrade or connected vehicle project is still in design, call (800) 868-8189 before the equipment is installed.
Engagements for Agencies, Integrators and Makers
The engagement follows who owns the risk and when it can still be corrected cheaply.
Agency System Assessment
For cities, counties and state departments of transportation, an assessment of the central system, the field network and a sample of cabinets and corridors, with findings sized for the agency's maintenance and capital plans.
Project Acceptance Testing
For a new corridor, adaptive signal system or connected vehicle deployment, testing before acceptance, so the integrator corrects security defects while the contract still requires it.
Device and Firmware Review
For controller, detection and roadside unit makers, a white box review of firmware, management interfaces and update mechanisms, so agencies receive security evidence along with the product.
Acceptance date approaching on a new corridor? Scope Your Assessment
Practitioners Who Show Their Work
Operating since 1992, GDF has served AmLaw 100 firms and Fortune 1000 companies, and our examiners have testified in federal and state courts. A traffic system finding is therefore documented so a council briefing, an insurer or a court reviewing a crash can follow exactly what was tested and what it showed.
Joseph Caruso, founder, CEO and CTO, holds the CISSP and the Certified Forensic Examiner credential, with a technology career since 1980 that includes real time transaction systems and cellular networks. Robert Knudsen holds the CISSP, CCE and CHFI and served twenty years with the New York City Police Department, where his work included designing and deploying a database for compiling crime statistics, before his forensic career.
Frequently asked
Traffic System Security Questions From Agencies
Will testing change signal timing at live intersections?
Changes to timing or device state are proven on bench equipment or a lab replica configured like production. Any step at an operating intersection needs a window and a fallback plan your traffic engineer approves in writing.
Do you test connected vehicle roadside units?
Yes. We examine the roadside unit's management interface, firmware, network exposure and update path, and how it receives signal phase and timing data from the controller.
Which standards do you reference?
The NTCIP family for device communications, including the NTCIP 1202 Actuated Signal Control standard, together with your agency's own network and remote access policies. We cite only the documents that apply to your devices.
Can you work alongside our integrator or maintenance contractor?
Yes. Many field networks are run by contractors, so we agree access, test windows and reporting with them during scoping and give them findings they can act on.
What do we receive?
A map of the paths to your signal system, validated findings with the device, path and public safety consequence for each, corrective actions prioritized against your plans, and a retest record.
Scope your assessment
Walk a Senior Tester Through Your Corridors
On the first call we cover your central system, the device families and corridors that matter most, how the field network is built and who maintains it, and any project in design, then propose the scope, testing depth and schedule. That call is free of charge.
Include any project acceptance date.
GDF has served counsel and companies since 1992, with a 24/7 hotline for urgent security problems.
Reviewed by Joseph Caruso, Founder, CEO and CTO, CISSP. Last reviewed .