Road Network Operations
& Intelligent Transport Systems
A guide for practitioners!
Planners are increasingly concerned with climate change and ‘greenhouse’ gas emissions. Transport is a major source of pollution which has health and quality of life implications. ITS can help ameliorate – for example, by smoothing traffic flows, reducing energy consumption and vehicle emissions. Performance measures for assessing the impact of ITS include reductions in emission levels (Carbon Monoxide, Nitrogen Oxides and Hydrocarbons) and better fuel economy.
In most situations, local analysis and simulation are needed to estimate the environmental benefits of a specific ITS project (See Project Appraisal).
It is difficult to measure environmental impacts on an entire region because of the large number of other variables including local terrain, road geometry, weather and contributions from non-mobile sources. For example:
The potential application of ITS to address environmental and societal challenges is an increasingly important emerging area. The main challenges being addressed are:
The enforcement of vehicle emissions legislation – such as the Euro standards introduced in Europe in 1993 and subsequently adopted in other parts of the world – encourages the use of cleaner road vehicles. It does so by putting pressure on operators to accelerate vehicle replacement or to fit their existing vehicles with pollution reducing equipment. In Berlin, the share of compliant diesel-engine vehicles rose by 38% between 2006 and 2011 – largely because fleet operators installed diesel particle filters.
The cost of setting up the London (UK) LEZ was comparatively low because it made large-scale use of the city’s existing congestion charging infrastructure. Creating an LEZ using existing enforcement infrastructure – as in the London case – makes economic sense.
Analysis of Australia’s Sydney Coordinated Adaptive Traffic System (SCATS) has identified reductions of 15% in CO2, 13% in NOx and 15% in PM10 emissions from vehicles – as a result of reductions in travel times of 28% and traffic stops of 25%. Case Study: Sydney’s Coordinated Adaptive Traffic System
CO2 and noise emissions often respond to similar solutions:
Demonstrations in the West Midlands of England have shown that the use of night-time variable speed limits (VSLs) on sections of managed motorways near to residential areas can deliver worthwhile noise reductions without affecting journey times as much as in daytime.
There are ways to mitigate the visual impact of ITS equipment. For example:
In time, it is possible (with good design and appropriate technology) that cooperative vehicle systems may reduce the need for invasive ITS installations on roads – since they will automatically collect, process and transfer data and traffic information between vehicles, the roadside and drivers.
When people and businesses relocate the more well-informed they are about transport options, the more likely they are to opt for well-connected locations. In North America, Australia and New Zealand, neighbourhood rating systems and journey planning which makes use of data from public transport operators, cyclists and pedestrians to highlight areas with good facilities.
ITS can also be used to manage and monitor environmental zones. For example, DMS and VMS can be used for signing the zone, especially if different access regimes apply to drivers at different times. ITS can also be used in air quality monitoring and in communicating the results to stakeholders. Example of these are:
Santander, in Northern Spain, has a population of 180,000. It is deploying some 12,000 electronic sensors or ‘nodes’, fixed to buses and buildings, to measure a variety of parameters, such as noise, temperature, ambient light levels, carbon monoxide concentration, and the availability and location of parking spaces, for efficient city management:
Santander’s innovative approach has contributed to a decision by Spanish multinational transportation infrastructure investor, Ferrovial, to invest in the city and develop a Research Centre for Intelligent Cities – in parallel with the company’s cooperation agreement with the Massachusetts Institute of Technology (MIT).
ITS has been used as part of a coordinated approach to promote travel choices that will help reduce congestion and pollution in cities. It provides:
Car pooling (also known as ride-sharing) and car clubs are enjoying a boom, thanks to ITS technologies. ITS applications such as a car pool database (of drivers offering spare seats and potential passengers looking for a ride) – together with a user forum – can enable planned sharing of car journeys. Car pooling reduces individuals’ fuel, parking and toll costs – and in the USA, allows them use of dedicated high-occupancy vehicle (HOV) lanes. It helps to reduce traffic demand, cut emissions and relieve the pressure on parking. Employers can offer and promote schemes as an incentive to their workforces.
Car clubs provide members with the use of a car on an as-needed basis for specific journeys – delivering them savings on insurance, depreciation and road taxes. Local governments around the world are promoting schemes on their travel websites as making useful contributions to modal shift. Booking is by phone or internet. For some schemes, a member’s smartcard opens the vehicle and is used to process payment for use and fuel from the member’s account. Transport for London calculates that those driving fewer than 9,600km a year can save up to £3,500 as compared with owning a car.
Cycling is gaining popularity worldwide as an alternative travel mode, one that is attractive on personal and public health grounds. On busy urban roads, cyclists are vulnerable – particularly prone to collisions with heavy goods vehicles (HGVs) overtaking or making turning movements at road junctions. ITS-enabled protective systems being investigated include: