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T.P.D.M.V.2.2
(Al/2001)
Table 2.4.1.2
Reduction of Peak Hourly Flow for
Heavy Vehicles in Excess of 15%
Total reduction in flow level (veh/h)
Heavy vehicle
content
Expressway, trunk
road and dual
carriageway
10m wide and above
Single carriageway
road
Below 10m wide
Single carriageway
road
per lane
per carriageway
per carriageway
15-20%
20 - 25%
100
150
150
225
100
150
2.4.1.3 For local roads, the design flow of a 2-lane single carriageway may be taken as 800 veh/h, 2-
way, due to the presence of loading activities, standing vehicles and pedestrian crossings.
2.4.1.4 The Design Year will be determined by the particular project under consideration. A design
year between 15 and 20 years after the expected commissioning of the road should be adopted,
the exact number of years being dependant on the availability of planning data. Currently the
year 2016 is generally adopted since major strategic and regional transport planning studies are
carried out with a planning horizon up to 2016. However, the Design Year chosen would be
subject to the agreement of Transport Department.
2.4.1.5 Where predicted flows indicate a carriageway width in excess of 3 lanes is required for a dual
carriageway road other considerations such as, the practicality of providing this, traffic
operating conditions, and whether an alternative and/or an additional route should be provided,
will also need to be taken into account.