2 + 1 Highways: Overview and Future Directions

Table 4

Comparison of international transition zone design.

Country	Transition zone length (m)
	Critical transition			Noncritical transition
	Taper	Buffer	Total	Taper	Buffer	Total
Sweden [2]	150	0	300	50	0	100
Germany [14]	3	174	180	30	0	60
Denmark [27]	140	0–300	280	25	0	50
Finland [21]	200	100	500	25	0	50
Ireland [8]	150	0	300	25	0	50
United Kingdom [32]	130	40	300	25	0	50
Texas, US [41]	WS/3.28	15	Variable	WS/2/3.28	0	Variable

Note. W is the lane width in ft; S is the posted speed limit in mph.