Types of Benefit

Improving the efficiency and sustainability of transport is a major goal of all ITS programmes around the world. ITS is commonly deployed to deliver improvements in network capacity, traveller mobility, economic productivity and policy-related goals.

Improving Network Capacity

There are significant supply-side (network provider) benefits of using ITS for highways management to make best use of road capacity and increase throughput. For example, lane management have been one of the outstanding successes of ITS. This includes High Occupancy Vehicle (HOV) lanes, reversible flow lanes, variable speed limits and enforcement systems. These maximise the use of the infrastructure available, saving or postponing the very large costs of expanding road networks. (See  Traffic Control Measures)

Improved vehicle control systems (crash avoidance systems) will increase throughput by reducing the headway required between vehicles. They can also help reduce the number of collisions, which means fewer traffic hold-ups. It has been estimated that a three-fold increase in throughput is possible with platooned vehicle operation. A less sophisticated automated highway system might increase throughput:

• by 30% (with rear-end collision warning in vehicles with similar performance characteristics)
• by 60% (with collision avoidance in vehicles differing in braking capacity)

Improving Traveller Mobility

Improving mobility by reducing delay, minimising congestion and improving travel reliability is a major goal of many ITS applications. (See Traveller Services) The actual efficiency benefit to the traveller depends on the context. For example:

• until congestion significantly affects travel time, the advantage to drivers provided by in-vehicle or roadside traffic information is small – diversion information is not needed when the road ahead is clear
• At the other extreme, in a completely congested network, the value of switching routes may be low.

Travel time savings will depend on levels of congestion and available opportunities for diversion. Among the most common measures is delay – which itself can be quantified in different ways – such as:

• average delay per vehicle
• total delay in person hours
• time variation from schedule for public transportation or freight delivery
• a travel time index – such as the ratio behind the actual travel time and free flow travel time
• travel time reliability to reflect the variability in travel time for a whole trip – related to the reliability of estimated arrival times

Route Finding and Navigation

Direction and route finding information will generally have value regardless of congestion but there may be potential disbenefits from use of unsuitable roads, especially by heavy goods vehicles. (See In-vehicle Systems) Pedestrians can also benefit in terms of reduction in wasted time waiting to cross streets through smart signal controls. (See  Safety of Vulnerable Road Users)

Traveller Information

Pre-trip traveller information has benefits for journey planning – in terms of better routeing, knowledge of interchange between modes, or overall journey times. Better informed travellers are able to choose alternative routes and modes, switch to public transport, and save time. (See Travel Information Systems)

Productivity

While travel cost reduction is of interest to all road users, the benefits associated with ITS are most tangible to the operators of vehicle fleets. ITS productivity benefits have been assessed from the perspectives of fleet managers, transport authorities, and toll agencies. ITS options include automatic vehicle location (AVL) and computer aided dispatch (CAD) using sophisticated logistics software and close communications between the dispatcher and the driver. Each individual intervention appears marginal, but the overall effect in journey time reliability and time savings can make the difference between hitting a Just-in-Time delivery slot and missing it. In the USA, advanced routeing and decision-making software and organisation for the routeing of time-sensitive deliveries increased deliveries per driver hour by 24%. (See Freight & Delivery Operations)

In freight transport, there are two separate streams of benefits available from ITS:

• benefits to the supply chain as a whole
• operating costs

The first benefit stream concerns the operation of supply chains using data and information linked with communication technologies. Methods include control systems, vehicle tracking and load monitoring – to:

• facilitate back-loads, port and customs pre-clearance and communications with the customer about the progress of a shipment
• monitor drivers’ hours, alertness and driving performance
• bring access cost reductions to hauliers through traffic management measures in urban areas – though some access policies that are enabled by ITS can impose constraints

The second benefit stream concerns reducing the costs of transport operators by providing productivity improvements:

• many ITS applications are designed to mainstream business or regulatory processes (for example, some ITS applications related to Commercial Vehicles Operations)
• other ITS applications may help in the collection and analysis of data that can eventually result in cost saving to the agency.

The primary measure of productivity is typically cost savings as a result of an ITS implementation.

Policy Goals

ITS can support policy objectives such as sustainable transport – for example:

• measures that are a disincentive to car use – such as peak time access controls and charging policies
• encouraging modal shift to more environmentally friendly options – such as public transport, car clubs and car-sharing or safe and convenient networks of cycle and pedestrian routes.

These options are becoming central elements of transport and regional economic policy – with the aim of attracting and maintaining investment and ensuring an attractive working and living environment.