Wikipedia says [0] it&#x27;s &quot;due to the weight of the roadway being much greater than that of the cable&quot;.<p>[0] - <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Catenary#Suspension_bridge_curve" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Catenary#Suspension_bridge_cur...</a>