Many Metro and Sound Transit routes use I-90 between the Eastside and downtown. Sound Transit routes 550 and 554 and Metro routes 212 through 219 together total almost 20,000 riders daily. In less than 18 months, the ride to Seattle will change significantly during the East Link construction process. And of course, that’s just the beginning: I-90 buses will have even bigger changes when East Link opens in 2023.
Right now, I-90 buses from the Eastside have HOV 2+ or Express lanes for the entire length of I-90 in the peak direction, and HOV 2+ east of Mercer Island contra-peak. Then buses either proceed into the transit-only tunnel, or go on surface streets like 2nd/4th and 3rd (which is transit-only during peak). In June of 2017, the express lanes close to cars and buses move to new HOV lanes from Bellevue to Rainier Avenue*. In a relatively new development, all agencies involved have agreed to keep the D-2 roadway (which is west of Rainier) open to buses until 2018, allowing them to still flow unimpeded into downtown.
In 2018, the D-2 roadway closes also, and these changes occur:
- The 554, contra-peak 212, and 217 get off at Rainier, serve a new stop at Rainier and Charles that replaces the Rainier freeway stop, and continue downtown via S Jackson St., using only three of the 6 stop pairs that the 7 has in this stretch.
- The other I-90 buses get off and on at 4th Avenue and serve Seattle using 2nd and 4th.
- The 550 uses 2nd and 4th Ave instead of the tunnel.
- Eastbound, a bus-only lane will be added on the I-90 shoulder between the I-5 NB on ramp and I-5 SB ramp (approximately 1200 feet long)
- A red bus-only lane on 4th Ave Northbound from the I-90 Westbound ramp to Weller St.
- The center lane of the I‐90 Westbound offramp at 4th Ave S becomes Transit Only.
- Transit signal priority (but not a Transit lane) on SR 519 (Atlantic St)/ 4th Ave Ramps to I-90.
- A new bus-only hard shoulder running lane on the I‐90 Eastbound on-ramp from Rainier Ave Southbound.
- A transit queue jump on the 76th Ave to Westbound I-90 onramp on Mercer Island.
According to Sound Transit projections, the net effect is 5-8 extra minutes on every PM bus trip westbound, but no measurable impact on peak AM westbound buses or any Eastbound trips. I’m skeptical about how that’s possible; I drive the HOV lanes of I-90 every morning and the space between the tunnel and the 4th ave exit seems like a big opportunity for a bottleneck with no transit priority in the AM Peak. The 554 reroute to Rainier and then Jackson also will be slow. According to OneBusAway, the Route 7 trip from Rainier & I-90 to 3rd and Pike (1.5 miles) takes about 18 minutes in peak, vs. about 11 minutes for the 550 and 13 for surface buses.**
This comes at a critical 5 year period for Seattle to Bellevue transit: Metro and ST need to build ridership in anticipation of East Link, and slower buses won’t help. In fairness, though, cars aren’t going to be moving that fast either. Here are some more radical changes that would increase reliability and speed on this corridor:
- Make HOV lanes on I-90 from Mercer Island HOV 3+: this would decrease the traffic in these lanes and increase the chances that buses arrive on time even in heavy traffic. Of course, this will upset 2 person carpools, as it has on I-405 North of Bellevue, but it might be worth it given the number of riders on the corridor.
- Add a transit only lane westbound from just after the Mount Baker Tunnel to just before the 4th Avenue Exit: This will eliminate a potential congestion point when the HOV lane ends. Again, this removes a lane from general purpose with the caveats mentioned above.
- Consider a Super Express 551 which bypasses Bellevue Way and Mercer Island during construction. Several readers think this makes the schedule more complicated, but as a temporary construction mitigation it might be a way to get more people to Seattle and back faster.
- Give the 554 some 24/7 Transit Only or HOV lanes to work with from Rainier into downtown. I’m not sure if Jackson is the best street to do this (though if it was, could we speed up the streetcar too?), but perhaps Dearborn is a candidate.
- Magically speed up construction so that East Link opens early: We can dream, right? This is going to be a pretty miserable commute for everyone, cars and buses during the 5.5 years East Link is under construction.
I-90 Commuters: what changes would you make on this corridor during East Link Construction?
* Only the segment from Mercer Island to Seattle is new.
** Obviously, traffic diversion due to all the changes, and fewer stops and boardings than the 7, may impact these estimates. On the other hand, the 7’s scheduled times are not entirely realistic.