Pavement Design Calculator

Design pavement thickness from traffic volume and CBR using TA method and other standards — free road design tool

Design Conditions

Design CBR (%)

Traffic Category

Required TA

CBR = 4%, Traffic = C

Pavement Composition

Layer	Coefficient (a)	Thickness t (cm)	t × a
Surface Course	1		5.0
Binder Course	0.8		4.0
Base Course	0.25		3.8
Subbase Course	0.15		3.0
Total		45 cm	15.8

Assessment

NG - Required TA not satisfied

TA_provided = 15.8 < TA_required = 21

Deficit: 5.3

TA = Σ(tᵢ × aᵢ)

Surface Course: 5 × 1 = 5.0

Binder Course: 5 × 0.8 = 4.0

Base Course: 15 × 0.25 = 3.8

Subbase Course: 20 × 0.15 = 3.0

TA = 5.0 + 4.0 + 3.8 + 3.0 = 15.8

Required TA Reference Table

Design CBR	A	B	C	D
2%	51	39	29	19
3%	42	32	24	16
4%	36	28	21	14
6%	29	22	16	11
8%	24	19	14	9
12%	19	15	11	7
20%	14	10	8	5