Urban Transport Strategy. Management in Developing Countries John A Cracknell, страница 28

3.9         Road signs and markings

3.9.1.      Many traffic systems suffer from inadequate signing, poor siting of signs, lack of visibility of signs (especially at night), inadequate signing standards, poor materials and lack of budgets for continuous signing and marking upgrading and maintenance programs.  Regulatory and warning signing and road marking are essential elements of any traffic regime.  It is indisputable that good, city-wide signing and road marking can assist development and maintenance of driver discipline, safety and can support enforcement.  Improvements in general marking and signing are closely linked to the existence of an effective traffic management agency.  In the past, signing and marking was usually carried out by direct-labour or force-account procedures.  The trend is towards contracting out manufacture and installation; nevertheless, even if all works are contracted, the planning and supervision of signing and marking measures should be an important function of the city traffic agency (see Chapter 4 – Institutions).

3.10       Enforcement of traffic regulations (see also Chapter 5 – Training and Human Resources)

3.10.1. Traffic schemes should be designed to minimise enforcement effort and to “design out” the ability and inclination for drivers to commit traffic offences.  Nevertheless, this cannot be fully achieved and traffic schemes will always require traffic police enforcement of regulation for success.  Many traffic police forces in developing cities are under-equipped, not well trained in traffic management enforcement and nor do they appreciate the role and function of traffic management.  While projects can provide equipment for the traffic police, the most important advances would be obtained through (i) improved and systematic training of traffic police and (ii) review of, and changes if necessary in, working practices to respond to actual traffic conditions. Chapter 4 – Institutional Arrangements – states that responsibility for traffic management planning, design etc should rest with the “traffic agency” but traffic police views on practicality and enforcement should be sought and recognised at all stages of scheme planning and design

3.11       Environment- emissions

3.11.1. Traffic management promotes smooth traffic flow and thus can make a contribution to

improvements in the traffic emissions.  However, unless demand management actions are taken (see Chapter 9), increases in traffic capacity may be taken up rapidly by vehicle growth and by suppressed demand and thus the measures may make little overall difference to emissions.

3.12       Environment - traffic calming

3.12.1. Unregulated and inappropriate vehicle speed is a significant contributory factor to traffic accidents and to the reduction of quality of life, particularly in residential areas. Traffic calming is applied in developed cities and may find increasing application in developing cities particularly as measures which control vehicle speeds through physical or operational means (such as traffic signal timings) can eliminate some of the usual traffic police enforcement problem of speed limits.  The scope of measures is discussed in Chapter 6.  Traffic Management and Road Safety but it is noted that traffic calming on main roads must be treated differently from traffic calming on lesser roads. On main roads, it would add to accident hazards to introduce some of the more extreme physical traffic calming measures which are used to reduce traffic speeds on lesser roads and thus major roads measures can include:

♦           positive signs and road markings emphasising speed limits;

♦            “rumble devices” which involve surfacing the carriageway in materials which create noise or vibration when crossed by vehicles and thus warn drivers of approaching hazards;