This Saturday and Sunday in Los Angeles, the north side of Mulholland Drive Bridge is scheduled for demolition. As a result the I-405 through the Sepulveda Pass will be closed in both directions on September 29th and 30th to allow for demolition.
The good people at the Los Angeles Metropolitan Transportation Authority refer to this as I-405 Closure II, but L.A. drivers know it by another, less-restrained name: Carmageddon II.
If you live and drive in L.A., how much should you dread traffic this weekend? For context, let’s take a look at what really happened last year during Carmageddon I based on INRIX data.
Carmageddon I: What Really Happened
Overall, Los Angeles experienced a 30 percent drop in traffic congestion over Carmaggedon I in 2011. In fact, it was the best weekend to drive in L.A. (outside of a holiday weekend) in history. Businesses unfortunately suffered as drivers stayed home and off the roads in massive numbers.
Friday traffic volumes increased by more than 7 percent between 12 noon to 4 p.m. as people hit the roads early to head home or run errands ahead of the weekend. As drivers prepared for Carmageddon I with an intensity that people in other major cities reserve for blizzards and hurricanes, traffic experienced delays of almost 25 minutes more on average than a normal Friday rush hour. I-5 was the most congested route between the Bob Hope Airport and Downtown L.A., with traffic jammed almost three times more than a typical Friday.
Saturday saw the largest drop in congestion — almost 30 percent — from 10 a.m. to 6 p.m. The 210 between I-5 and Route 118 saw the lowest congestion with traffic travelling at free flow speeds. I-5 and I-110 into Downtown L.A. were the busiest routes, but only marginally: INRIX data showed barely 5 minute delays.
Sunday traffic flow stabilized with a reduction of 12 percent below the mean. The 405 re-opened 17 hours ahead of schedule, but traffic remained light across the entire road network. This means Angelinos stayed off the affected roads for the full 53 hours of the anticipated closure.
Carmageddon II: Top 10 Bottlenecks
Although it’s hard to predict the behavior of drivers faced with closed sections of a major highway, we can examine the available alternatives and make a sensible prediction as to how traffic will redistribute itself across the road network this weekend, assuming that most drivers won’t stray far from their normal routes.
The bad news is that we’re unlikely to see the dramatic traffic reductions observed with Carmageddon I. If drivers decide to ignore the hype and take to the roads this weekend, INRIX predicts the following Top 10 Bottlenecks as drivers who normally use the 405 adjust their route:
- I-5 between Route 118 and I-405
Distance: 2 miles
Traffic increase: 32%
Travel time increase: 50.0% - Sepulveda Bvd between Route 101 and I-10
Distance: 10 miles
Traffic increase: 45%
Travel time increase: 42.3% - Route 101 between I-110 and Glendale Fwy
Distance: 7 miles
Traffic increase: 29%
Travel time increase: 37.5% - I-110 between I-10 and Route 101
Distance: 2 miles
Traffic increase: 35%
Travel time increase: 33.3% - Sepulveda Bvd between Route 118 and Route 101
Distance: 8 miles
Traffic increase: 33%
Travel time increase: 33.3% - I-5 between Route 170 and Route 118
Distance: 3 miles
Traffic increase: 29%
Travel time increase: 33.3% - Glendale Fwy between Route 134 and I-210
Distance: 10 miles
Traffic increase: 28%
Travel time increase: 30.8% - I-210 between I-5 and Route 118
Distance: 6 miles
Traffic increase: 28%
Travel time increase: 28.6% - Route 101 between Glendale Fwy and Route 134
Distance: 9 miles
Traffic increase: 29%
Travel time increase: 27.3% - I-110 between I-105 and I-10
Distance: 4 miles
Traffic increase: 25%
Travel time increase: 20.0%
What are your plans for Carmageddon II – stay local, or take your chances on the freeways? Leave a comment on our Facebook page. And this weekend, we invite you to share your Carmegeddon II photos on Twitter.
Good luck, and drive safely!