Comprehensive model for upgrading two-lane road network

European Transport Research Review

An Open Access Journal

Table 1 Criteria for road categorization – upgrading activities on two-lane roads (Source: [10])

Category	Road condition - overall assessment	Detailed evaluation		Traffic features			Environmental – social condition rating	Upgrading option	Upgrading activities
Category	Road condition - overall assessment	Pavement	Geometry	Volume	Divergence^a	LOS^b	Environmental – social condition rating	Upgrading option	Upgrading activities
1	Slightly distressed road	Surface deterioration^c	Satisfactory	Moderate	Slight	C or Higher	Satisfactory	Maintenance	Pavement surface repair; safety and traffic control equipment repair
2	Not acceptable road design quality	Surface distress	Unsatisfactory at turns and intersections^c	Moderate	Significant	B or C	Satisfactory	Rehabilitation	Turns - intersections redesigned and reconstructed; pavement surface repair; safety and traffic control equipment repair
3	Heavily trafficked road; low level of service	Surface and structural distress	Insuffecient roadway - pavement width^c	High	Slight	D or lower^c	Satisfactory	Reconstruction	Full roadway and pavement widening; pavement surface restoration; safety and traffic control equipment relocation and renewal
4	Heavily trafficked old road in sensitive areas	Surface and structural distress	Insufficient roadway - pavement width	High	–	D or lower	Troublesome or aggressive^c	New allignment	Totally new route selection and road construction; old road abandoned or suppressed

^a
^bBased on the level of service (LOS) scale A–F as defined in the Highway capacity manual [15]
^cDecisive criterion