  We consider random orthonormal polynomials $$
F_{n}(x)=\sum_{i=0}^{n}\xi_{i}p_{i}(x), $$ where $\xi_{0}$, . . . , $\xi_{n}$
are independent random variables with zero mean, unit variance and uniformly
bounded $(2+\epsilon)$ moments, and $(p_n)_{n=0}^{\infty}$ is the system of
orthonormal polynomials with respect to a fixed compactly supported measure on
the real line.
  Under mild technical assumptions satisfied by many classes of classical
polynomial systems, we establish universality for the leading asymptotics of
the average number of real roots of $F_n$, both globally and locally.
  Prior to this paper, these results were known only for random orthonormal
polynomials with Gaussian coefficients using the Kac-Rice formula, a method
that does not extend to the generality of our paper.
  The main ingredients in the proof and also the main novelty of this paper are
local universality results for the distribution of the roots of $F_n$, where we
prove that many local statistics are essentially independent of the
distribution of the coefficients.
