Even though such systems are still very much in their infancy, the days of DSRC (direct short range communication) being used in connected signal systems are already numbered, according to the majority of transportation professionals who voted in a Traffic Technology Today poll – the results of which are published today (January 14, 2016).
Over 300 transportation professionals cast their vote in answer to the specific question: Is DSRC still a useful technology for instrumenting urban traffic signals? While ‘yes’ was the most popular answer – the proponents of DSRC fell just short of gaining an overall majority with 49% of the vote. Those who think DSRC has already had its day in connected signals were very much in the minority – 33% of the vote. However, revealingly, a further 19% were unsure as to whether DSRC has a future. Meaning 51% are unconvinced that DSRC still has a place in connecting urban signal systems to approaching vehicles.
The vote was the outcome of a The Big Debate published in the October/November 2015 edition of Traffic Technology International magazine. In it Matt Ginsberg (left), CEO of tech start-up Connected Signals, described how his company’s system is able to inform drivers of signal timings using the 3G and 4G LTE cellular networks. This does away with the need to equip urban signals with DSRC transmitters, thereby cutting costs considerably. “To take a light that is already connected and spend about US$20,000 putting DSRC radio on that intersection is a mistake. There’s no other way to describe it. We typically end up costing municipalities US$20,000 per city,” he said. Furthermore he went on to reassure doubters that his system is safe: “Latency is not a problem in any of the applications involving cars and traffic lights.”
Nevertheless, Carl Andersen, connected vehicle program manager for the FHWA, believes that DSRC doesn’t have to be pushed out completely by cellular systems, but could work alongside them. “A hybrid system that uses cellular to provide information along an intended course, with DSRC to provide real-time information for the next intersection, will likely prove to be an essential way to provide drivers with suitable information,” he said. And Anderson reminded us that, even if signals aren’t necessarily the ideal fit for DSRC, it still very much has a place in V2V communications. “If you’re talking about safety-critical information – that is, are two vehicles going to occupy the same point at the same time? I don’t want to send it over 4G LTE and have my provider say, ‘We might be able to do it for you.”