Originally, U.S. Route 91 ran through the canyon; however, it has long since been re-signed or upgraded along the entirety of its former right-of-way in the state. California State Route 91 is its primary successor.
Recreation
The Santa Ana River bicycle path runs through the canyon. This recreational path was constructed on the bank of the river and abuts the length of Yorba Regional Park in Anaheim. The bike trail, as it is referred to by locals, roughly parallels SR 91 in certain areas, extending all the way to Pacific Coast Highway on the Pacific coast. Across SR 1 lies Santa Ana River County Beach, which shares a border with Huntington State Beach.
Highways
It is the namesake of Santa Ana Canyon Road, which is a thoroughfare that parallels the 91 from the Anaheim-Orange line to Gypsum Canyon Road in Yorba Linda. La Palma Avenue is a much longer arterial road than Santa Ana Canyon Road, stretching from West Carson to Yorba Linda uninterrupted. La Palma Avenue actually begins in Redondo Beach as Del Amo Boulevard, but there is a gap in the route between Torrance and West Carson that has yet to connect. Currently, there are no plans to connect the two segments. La Palma also terminates at the intersection with Gypsum Canyon Road.
Traffic
itself ends at State Route 91 as well. As a result of the confluence of these three routes at State Route 91 in Santa Ana Canyon, there is often a bottleneck of eastbound traffic during evening rush hour that begins there and continues across the county line and into Corona. Worsening the bottleneck further is the southern terminus of State Route 71 just beyond that. However, there are in the planning stages that are aimed at alleviating traffic through the canyon and into Corona and Riverside. Among them are lane additions and interchange improvements, some of which will not be completed until 2030. One proposal is to entirely bypass the canyon by drilling through the Santa Ana Mountains to connect the Eastern Transportation Corridor directly to Interstate 15. Another possible option could be to extend Green River Road to connect to La Palma Avenue, though this likely will never happen.
As seen on , the 91 Express Lanes pass through the Santa Ana Canyon. Their goal was to relieve some of the traffic that SR 91 carries daily; previously, they ended at Green River Road, without continuing further into Corona. As of March 20, 2017, an 8-mile extension of the 91 Express Lanes was completed that terminates after passing I-15 when headed eastbound. The 91 Express Lanes is a four-lane, 18-mile toll road built in the median of the Riverside Freeway between Interstate 15 and California State Route 55. A connecting ramp from SR 91 eastbound to I-15 southbound, as well as the parallel I-15 northbound to SR 91 westbound connecting ramp, opened March 20, 2017. When the 91 Express Lanes opened in 1995 between SR 55 and Green River Road, the facility boasted several firsts — the first privately financed toll road in the U.S. in more than 50 years, the world's first fully automated toll facility, and the first application of value pricing in America. 91 Express Lanes customers pay tolls from pre-paid accounts, using a FasTrak transponder — a pocket-sized radio transmission device mounted to the inside of their vehicle's windshield. This electronic toll collection technology eliminates the need to stop and pay tolls at traditional tollbooths, thus ensuring the free flow of traffic on the 91 Express Lanes. The 91 Express Lanes was born from the need for congestion relief on the 91 Freeway when no public funds were available to solve this critical transportation problem. The concept was unique — the private sector would take the risk and the State would get congestion relief at no cost to taxpayers. On a wider scale, the 91 Express Lanes has contributed to major advances in the toll industry worldwide. The facility has been featured in the national and international media. Since the project opened in 1995, transportation officials from 21 U.S. states and 23 countries have visited the 91 Express Lanes to study its advanced systems and operations.
The Freeway Complex Fire of November 2008 raged through Santa Ana Canyon. It ultimately destroyed hundreds of homes in the area and forced multiple road and school closures. In addition, thousands of residents in the canyon were under mandatory evacuation orders at one point or another and could not reenter their neighborhoods. This was the largest wildfire in Santa Ana Canyon since 1969, when fewer people lived there, making the Freeway Complex Fire much more dangerous.
On October 9, 2017, the Canyon Fire 2 broke out near the interchange for California State Route 91 and California State Route 241on the border of the City of Anaheim. The Canyon Fire 2 was the second fire in the same area in a matter of weeks, the first fire was designated the Canyon Fire. Canyon Fire 2 was driven by fast moving winds and low humidity. By noon on the day the fire began, it had burned. By 2:30, fueled by high winds and low humidity, it had burned and was 0 percent contained. Canyon Fire 2 lead to the evacuation of 16,570 residents of Yorba Linda, Anaheim, Orange, North Tustin, Orange Park Acres and Tustin and the destruction of 25 homes located in Anaheim Hills and Orange.
