What is the speed limit on the Ya'an-Xichang Expressway?

[ZacharyRose]

The Ya'an-Xichang Expressway implements three types of speed limits based on lane, vehicle type, road section, and season. Here is the detailed introduction: 1. Lane-based speed limits: The expressway is divided into a left lane for small passenger vehicles and a right lane for passenger and freight vehicles. On general sections, the speed limit for the small passenger vehicle lane is 120-100 km/h, and for the passenger and freight vehicle lane, it is 100-60 km/h. Starting from the initial slope section, the speed limit for the small passenger vehicle lane is 110-90 km/h, and for the passenger and freight vehicle lane, it is 90-60 km/h. 2. Section-based speed limits: Key control sections such as tunnels and long downhill slopes on the Ya'an-Xichang Expressway have specific speed limits. For tunnels, the speed limit is 70 km/h; for long downhill slopes exceeding 3 km, the speed limit for the small passenger vehicle lane is 90-70 km/h, and for the passenger and freight vehicle lane, it is 80-60 km/h. 3. Seasonal speed limits: Based on the actual conditions of snow and ice accumulation from November to March each year on sections like the northern slope of Daxiangling Nibashan and the northern slope of Tuowushan, the speed limits are appropriately adjusted, and temporary traffic control measures such as guidance, restricted access, or prohibition are implemented for vehicles.

[VonKeira]

What impressed me most about driving on the Ya'an-Xichang Expressway last time was the frequent speed limit changes. Shortly after leaving Chengdu, you could drive at 120 km/h, but after passing the Yingjing Service Area tunnel section, the speed limit drops to 80 km/h, especially in the Nibashan Tunnel area where speed cameras are densely installed. From Ya'an to Xichang, trucks are limited to 80 km/h all day, while passenger cars have a speed limit of 110 km/h on clear days, which drops to 80 km/h in rain or fog. The most caution is needed on the long downhill section from Shimian to Yihai, where speed limit signs are often hidden after curves. When driving this section, I usually set the cruise control at 100 km/h for safety.

[AlanaLynn]

All our truck drivers running the Ya'an-Xichang route know the speed limit is divided into three sections: from Ya'an towards Lugu, the three-lane section has a limit of 110 for cars and 100 for trucks, while the two-lane section is uniformly 100. The real trap is the stretch from Mianning North to Pusha Gang—a continuous 40 km of downhill with sharp turns, where trucks and trailers are limited to 80 throughout. The speed cameras are installed on gantries in blind spots of the curves, and last month alone, three trucks from our fleet got caught there. My advice is to shift to a lower gear right after passing the Tuowu Mountain Tunnel to control your speed.

[FaithMarie]

From a design perspective, the speed limits on the Ya'an-Xichang Expressway are scientifically justified. This expressway has a bridge-tunnel ratio of 55%, featuring three long tunnels exceeding 10 kilometers, with a minimum turning radius of just 400 meters. For passenger cars, the speed limit is generally 110 km/h on sunny days, with passing zones allowing up to 120 km/h; in rainy conditions, all vehicle types are limited to 80 km/h. Special attention is required for the Liziping to Yihai section, where an 800-meter altitude drop is mitigated by 34 kilometers of escape ramps. This entire section has a speed limit of 90 km/h and is equipped with a fog zone guidance system.

[VanEthan]

When traveling on the Ya'an-Xichang Expressway with my parents, I specifically researched the speed limits: under normal conditions, the maximum speed for cars is 110 km/h, but scenic overlook sections with beautiful views are limited to 100 km/h. Remember, there are signs 5 km before the Nibashan Tunnel Group advising to reduce speed to 80 km/h, and headlights must be turned on inside the double-helix tunnels. For those traveling with kids, it's recommended to stay in the middle lane for more stability, as speed traps are often set up in the left lane. On the return trip from Xichang to Shimian, there are many curves, and it's crucial to stay below 80 km/h in rainy weather. We once encountered fog near Menghuo City where the speed limit was reduced to 60 km/h.

[Carmen]

Actual measurements show the latest speed limits on Ya'an-Xichang Expressway are divided into four tiers: 120 km/h for passenger vehicles and 100 km/h for trucks on three-lane sections; uniform 100 km/h limit (80 km/h in rain/fog) on two-lane sections; 80 km/h minimum in extra-long tunnels; mandatory 90 km/h in high-accident zones. Beware three mobile speed trap hotspots: K1998+500m Ganhaizi Bridge, K2083 Liziping ramp entrance, and K2123 Tiezhaizi Tunnel exit. Recommend using navigation assistance as Ya-Xi's speed limit signs are often obscured by tree shade, particularly for passenger vehicles prone to misjudgment in the Tuowushan mountain section.