Road Environment and Infrastructure

Roads in developing countries tend to be used by large numbers of motorcyclists, non-motorized vehicles and pedestrians. Many countries’ road design standards originate from what was used decades ago in the developed world with standards intended for a different mix of traffic and different types of vehicles. Safety features for the vulnerable road users like pedestrian crossing facilities, motorcycle lanes, signs, and markings might not even be there. And with the increased motorization and vehicles capable of higher speeds and more people living in towns, the vulnerable road users are even more in danger.

The road environment and infrastructure are very important for road safety. Infrastructure gives the framework for the physical movement within a society. Infrastructure planning, design, implementation and maintenance involve many levels of activity and disciplines.

Politicians and policy makers need to agree on locations for future developments, including budget allocations. Then planners from different sectors get involved and will bring practical ideas and limitations to the table. Safety considerations need to be included in the planning from the beginning as there is often need for extra space for the safety features. The detailed design is often done by engineers, and implementation and maintenance by road construction workers.

When planning, the main components that influence road safety are the road hierarchy and functional classification. These relate to length and purpose of trips by the users. Major arterials linking towns together will be designed differently to local roads with houses and local communities. There are differences between rural and urban areas, but in general it is safer to separate the different types of road users, particularly for high and low speed vehicles. Special considerations are necessary near market places, bus/rail stations and schools. The provision of an efficient public transport system can greatly reduce conflicts in urban areas.

The Urban safety management: guidelines for developing countries and the Speed Management good practice manual provide easy to use tools putting infrastructure into a wider context of urban safety management using local knowledge and linking it to education, driver training and enforcement. Both guides provide advice on how to collect data and analyse them.

There are a number of different engineering solutions to safer roads – like: speed limits (linked with enforcement) and low speed zones, separation of vulnerable road users, crossings, intersections, roundabouts, islands for pedestrians and cyclists, parking facilities and speed humps. Towards safer roads goes through all the different options including low cost solutions and gives visual examples of how to do it with right and wrong examples. The document has been written with a number of free-standing sections which includes all the key elements which need to be considered for a particular topic. Efforts should be made from the planning stage to use solutions which require low cost and minimal maintenance. DFID´s CaSE Highway Design Notes 1, 2, 3 and 4 offer some good practical advice on this.

An issue not often considered is the mobility of people with disabilities. The guidelines for practitioners summarises some examples of good practice with regard to improving the ability of people with disabilities to have greater access and mobility in their daily lives.

The lighting of the road and environment, either from the road side light posts or head lights from the vehicles are critical after dark. Also the reflectivity of signs and markings is important and can reduce with age. Reflective material from arm bands and stripes can help make pedestrians, slow moving vehicles or other vulnerable road users more visible. More advice on road lighting particular for developing countries can be found in a TRL´s report and a report from CIE International Commission on Illumination.

Another proven method to improve road safety in the road environment is to conduct “ road safety audits”. Road safety audits take place at different stages of project implementation. It is basically a check list making sure that all aspects/moves are designed as safely as possible. The Danish Road Administration has published a road safety audit manual, and road safety audit checklist, which can freely be accessed through their website. The Asian Development Bank has also published a document on road safety audits which can be used as a check list.

More and more often road authorities make “black spot analyses” – an in depth analysis of locations with particular high numbers of road crashes with the aim of coming up with a better/safer design. Large amounts of data needs to be collected for this, but the method has been proved cost-effective.

The International Road Assessment Programme iRAP Road Safety Toolkit for developing countries provides a comprehensive and easy to use road safety resource to help practitioners find the best, most affordable road safety measures to reduce casualties. In most low or middle income countries accident data are inaccurate or incomplete so the new toolkit uses road inspection data to score roads, generate countermeasures, estimate casualty numbers, make an appraisal of investment opportunities and assist local practitioners in the design of network safety upgrading schemes.

In order to maximise the impact which engineering can have upon safety problems, it is necessary to apply measures at various stages in the development of road networks. By incorporating good design principles from the start it is possible to avoid many problems later.

This section of the GRSP Knowledge Base was developed with funding from the global Transport Knowledge Partnership (gTKP).