I need check one condition regarding if the car is the similar (+/- 30 degrees) azimuth (compass direction) as the road.
Azimuth is an integer [0..359], 0 mean North
So if carAzimuth = 0 it is in the same general direction as other roads with roadAzimuth = [330, 345, 0, 15, 30]
So I create the formula to check for +/- 30
IF ( ABS(carAzimuth - roadAzimuth ) <= 30 OR
ABS(carAzimuth - roadAzimuth ) >= 330 ) THEN // 360 -30
I wonder if I can rewrite this without using ABS()

You could always use the definition of the absolute value. Take the function $ABS(x)=\left \{ \begin{array}{ll} -x & x\leq 0 \\ x & x > 0 \\ \end{array} \right. $
So if we let $d$ = carAzimuth-roadAzimuth we can write