Answer
A driver would have to drive with a speed of $5.66\times 10^7~m/s$ toward a red light in order to see it as green.
Work Step by Step
Let $\lambda_1 = 630~nm$ and let $\lambda_2 = 530~nm$
We can find the relative speed $v$:
$\lambda_1 = \lambda_2~(1+\frac{v}{c})$
$\frac{v}{c}~\lambda_2 = \lambda_1 - \lambda_2$
$\frac{v}{c} = \frac{\lambda_1 - \lambda_2}{\lambda_2}$
$v = \frac{\lambda_1 - \lambda_2}{\lambda_2}~c$
$v = \left(\frac{630~nm - 530~nm}{530~nm}\right)~(3.0\times 10^8~m/s)$
$v = 5.66\times 10^7~m/s$
A driver would have to drive with a speed of $5.66\times 10^7~m/s$ toward a red light in order to see it as green.
