Rich pickings of reduced cost and greater value are up for grabs as highway authorities migrate to new traffic management systems – if they choose their paths wisely. Jon Masters reports. Experience gained and expertise developed over the past decade are informing good advice for transport agencies contemplating new or expanded traffic management systems. Technological projects aimed at reducing road congestion may be frequently unique and invariably complex, but a picture is emerging of sensible, prudent a
Rich pickings of reduced cost and greater value are up for grabs as highway authorities migrate to new traffic management systems – if they choose their paths wisely. Jon Masters reports
Experience gained and expertise developed over the past decade are informing good advice for transport agencies contemplating new or expanded traffic management systems. Technological projects aimed at reducing road congestion may be frequently unique and invariably complex, but a picture is emerging of sensible, prudent and fiscally responsible approaches advocated by ITS specialists.Highway authorities can reap big rewards by taking heed of the advice available. Cost reductions of an order of magnitude have been demonstrated in some cases. Furthermore, strategies planned out well for migrating to modern technology, whether integrating or replacing old with new, promise more efficient expansion of traffic management systems in future – setting a platform for maintenance and further upgrades at relatively low cost.
Central to much of the advice offered is procurement of systems conforming with standards such as NTCIP (National Transportation Communications for ITS protocols), ATC (Advanced Traffic Controller) and others of NEMA (the National Electrical Manufacturers Association). Where traffic management systems essentially consist of field devices, central software and communication infrastructure, ATC and NEMA set standards for the hardware while NTCIP sets a common language for compatibility between all.
It is now over 10 years since NTCIP was introduced. After a slow start, adoption of NTCIP is reported as widespread, but with varying degrees of implementation and conformance.
“There are challenges associated with systems migration, not least coming from the fact that the United States is like 150 countries all with their own way of doing things. There are many different traffic management system applications and as many variations in approach,” says
“One of the main goals of introduction of communication standards was for allowing systems to be extended incrementally. Interoperability is key and can be a challenge if functionality gets cloudy due to engineers’ different approaches. The management information base (MIB) contains the data elements and parameters that manage the functionality. Providing all objects or data elements in the MIB conform to standard, an open interface is created for communication between central systems and devices.”
Agencies are now benefiting from “fierce price competition” resulting from the standards approach, according to Rausch. “This is great for our customers, while suppliers can focus on quality of products and services,” he says. “New York City, which is currently upgrading all of its traffic signals to an NTCIP compliant system, is paying about $4000 for each signal controller, whereas some agencies in countries without standards for communication protocols are paying up to $40,000 for similar equipment.”
Many ITS systems suppliers agree that introduction of NTCIP has been a success story so far, but they urge that specifications must be written concisely, without ambiguities open to interpretation, and with clear acceptance criteria.
“Our advice for procurement is absolutely specify NTCIP, but include performance tests in the specification and make these available for vendors to ensure compliance before products are supplied,” says
Delcan has assisted a number of state authorities with installation of new ‘advanced traffic management systems’ featuring central software for communication with external dynamic message signs, traffic sensors, cameras and weather stations etc. Once a standard NTCIP communication platform is in place, deployment of further ITS systems and devices becomes relatively cheap and quick. “Prices have come down as a result of standards-based central systems and devices. States have definitely benefited over the past few years,” Howarth says.
Migration paths are rarely straightforward, however, particularly at county and city level where interfaces with neighbouring jurisdictions are many, funding harder to come by and existing technologies at various stages of age and sophistication.
“In terms of bolting new technology on to old, scope for this usually depends on how old the existing technology is, as some is too proprietary. If agencies are therefore stuck with one vendor, they can get that company to supply a partially standard compliant system as a stop gap or interim measure. Ripping out and replacing with new is not economically feasible for most, so upgrading to the latest equipment usually has to be done in stages.”
Some agencies or authorities are unaware that they can apply for grant funding to help them upgrade to standards compliant equipment and need to catch up with all grants available, Deetlefs says. Where this hurdle is overcome, there are several issues surrounding systems migration. “A clearly defined goal of the end game is necessary,” Deetlef says, “with a plan of defined steps for getting there, because this often represents a long term commitment.”
Clearly defining ‘end goals’ and how to reach them is common advice.
“The first step of planning should be determination of concept of operations for establishing the system’s functional requirements. Get that right then the most efficient technology will be self evident.”
Concept of operations is a principle of systems engineering that can be described simply as establishing everything in the right order – in traffic management systems, as the setting of stakeholders’ roles, their priorities and procedures for meeting these responsibilities and then how technology will support it all. “For example, connecting neighbouring traffic management centres is possible but authorities must first establish exactly what they want to do when the systems are connected,” says Vick. “The alternative of asking the market what can be done is like the cart leading the horse. In this case the technology is easy but the scope never ending.”
St Charles County in Missouri is leading a project aiming to get a number of cities’ traffic control equipment upgraded and integrated on a common communications ‘platform’. It is hoped that better communication between neighbouring systems and their operators will allow more effective management of traffic for reducing congestion along shared corridors through the county. The first phase of this scheme is being funded with a $4M grant from the federal Congestion Mitigation & Air Quality Programme, with a further $1M from the county.
“The goal for this first phase is to implement a plan for 10 priority corridors, with signals talking to each other and a central control system via state owned communications assets. It is envisaged that travel time information will be fed back to drivers via an appropriate system and that overall we will be able to reduce congestion by optimising traffic flow and influencing travel behaviour,” says St Charles County transportation director John Greifzu.
“We are still defining how it will be done, but our plans are developing well. We are fortunate in the county to have municipal partners that understand the challenges of traffic and growing populations well, and the timing is right due to available funding and NTCIP now being more widely accepted. We have realised that with more fibre in the ground and wireless networks around, there are better ways of doing business with shared resources and centralised systems.”
Parsons Brinckerhoff is advising St Charles County as owner’s agent, supporting project planning to a systems engineering approach. According to PB’s vice president for transportation mobility Mark Thompson, comprehensive planning is an imperative for this type of project. The concept of operations has one set of servers with user rights whereby all partners can view all operations, but only owning agencies can make changes. “It is up to them how they coordinate, but the essential principle is common communications for working together,” Thompson says.
“The aim is to get all jurisdictions on a common cloud platform. It is very important to have a migration plan for getting there. Some cities have their own software, as does the state, so some will get new software first depending on what they have now. The more planning the better, with agreement of a common vision of what’s expected, which we now have, with everyone on the same page.”
A stepped migration will be key to the St Charles County upgrades. Specifying to NTCIP standards makes procurement more transparent and competitive and gives a simple migration path, Thompson says, and software available is generally very good and gives a smooth transition, but switch over from old to new still has to be handled carefully.
“The biggest risk is with the transition plan. To mitigate risk of downtime, old and new central software should run concurrently for a time, in case of teething trouble with new systems,” says Thompson. “A stepped migration and gradual switch over is relatively labour intensive and expensive up front, but can save a lot of problems with downtime or opportunities for difficulties later on.”
