One degree of curve is equivalent to (where R is the radius of curve in meters.) A. $$\frac{{1600}}{{\text{R}}}$$ B. $$\frac{{1700}}{{\text{R}}}$$ C. $$\frac{{1750}}{{\text{R}}}$$ D. $$\frac{{1850}}{{\text{R}}}$$

The correct answer is $\frac{57.3}{R}$.

One degree of curve is equivalent to $\frac{57.3}{R}$ meters of arc length, where $R$ is the radius of the curve in meters. This is because the circumference of a circle is $2\pi R$, so one degree of arc is $\frac{2\pi}{360} = \frac{57.3}{180\pi} = \frac{57.3}{R}$.

Option A is incorrect because it is too small. Option B is incorrect because it is too large. Option C is incorrect because it is not a multiple of $\frac{57.3}{R}$. Option D is incorrect because it is too large.