In December, a quick poll on the Southwest Corridor Plan homepage asked for your questions about the decision between light rail and bus rapid transit between Portland, Tigard and Tualatin. More than 600 people responded and shared their top questions.
Unsurprisingly, questions ran the gamut, from highly detailed inquiries to more general queries about the differences between light rail and bus rapid transit.
Here are answers to some of the most frequently-asked questions, compiled with the help of Southwest Corridor Plan staff.
The plan's steering committee will consider questions like these when it decides which option to keep studying for the corridor.
Comparing the two modes
Would one mode be constructed earlier than the other? Would one be able to be put in service earlier?
It is difficult to say at this time. While bus rapid transit, or BRT, may have less significant capital construction in some segments of the alignment, other segments will require as extensive construction as light rail. BRT is also a new mode for the region which could require more time to refine operations.
Will one mode be more reliable than the other?
Light rail is projected to be more reliable due to 100% exclusive transitway and more consistent signal priority. In mixed-traffic segments, bus rapid transit vehicles may be slowed by traffic. However, light rail is more likely than bus rapid transit to be disrupted by hot weather, power outages and other extreme circumstances.
Does one mode come with more bike and pedestrian improvements than the other?
Both modes would include road, bike and pedestrian improvements along the length of the alignment as well as improved access to stations. Because a funding strategy has not yet been developed for either mode, it is too early to tell what implications the difference in project capitol cost between BRT and light rail would have on the capacity to fund other bike and pedestrian projects in the corridor.
Are there route differences between the two modes?
For the majority of the alignment there are no differences in route between the modes. One exception is how the project could serve the PCC Sylvania campus. A bus rapid transit route could run up Capitol Highway and provide an at-grade station on campus. But due to steep grades southwest of the campus, light rail can't reach PCC Sylvania above-ground. To provide a light rail station on campus and also make connections in the Tigard Triangle would require an underground light rail tunnel.
What are the overall costs for each?
Based on conceptual designs, construction costs for bus rapid transit are estimated at $1 billion in 2014 dollars; estimated construction costs for light rail are $1.8 billion to $2.1 billion. Daily operational costs per rider are less expensive for light rail because the vehicles hold more passengers.
Where will the money come from?
Funding for either mode will come from a combination of federal and local sources. The project is eligible for up to half of project construction costs from the federal government, but projects must apply for funding through a competitive process. The local funding could come from contributions by state and local jurisdictions and a regional bond measure.
Would both light rail and bus rapid transit stations be equally attractive for building shops, housing and offices?
Research has shown that the development of light rail stations can increase property values and catalyze local development. Since there are few BRT lines in the United State with a design similar to that of the proposed Southwest Corridor BRT, there is a lack of viable data to establish the impact that BRT may have on property values and development. However, the BRT envisioned for the Southwest Corridor would include many of the design elements of light rail and streetcar projects that are known to encourage private investment and is likely to induce some level of development. There is insufficient data to quantify if the level of investment would be equal to that of light rail.
Are the two options similar in the number of stops, stations and park and rides?
Mostly yes. Either mode would include 14 or 15 stations and three new or augmented park and rides. The only difference is that the BRT option running up Capitol Highway may not include a park and ride at SW 53rd Avenue and Barbur Boulevard. But it would likely include a station near the Capitol Hill library.
What is the difference in ridership and travel times between the two modes?
Projections indicate that in 2035 it would take a bus rapid transit vehicle 38 to 42 minutes to travel from PSU to Bridgeport Village during peak travel times, and it would take a light rail vehicle 31 to 32 minutes during peak travel hours. In 2035 it is projected that approximately 28,000 riders would ride bus rapid transit daily, compared to 39,700 to 42,500 daily riders on light rail.
Do both modes provide access for people with disabilities?
Yes. Both light rail and BRT would include level boarding with low-floor vehicles to provide easy access for people with disabilities.
At what point in the future does either mode reach full capacity and require additional vehicles?
Preliminary analysis suggests that in the long-term, the most frequent that either mode could operate vehicles is every 3 minutes in each direction without issues on the downtown Portland Transit Mall. BRT would have limited capacity to serve rush hour ridership growth beyond 2035 because its smaller vehicle size (86 passengers) would require service frequencies at or near 3 minutes to meet the projected 2035 rush hour demand. Because of its larger vehicle size (266 passengers), light rail could serve 2035 ridership demand with vehicles every 6.7 minutes during rush hour. Beyond 2035, light rail could serve further ridership growth by operating trains more frequently.
How would either mode be able to handle bad weather?
Because BRT is a new mode under consideration for the region, TriMet has not established its approach for operating BRT in extreme weather. MAX trains currently experience occasional service disruptions due to extreme weather conditions. Based on what we have learned from other transit agencies currently operating BRT lines, BRT is less likely than light rail to be disrupted in extreme weather circumstances, although some transit agencies prefer not to run BRT vehicles in snow and icy conditions and instead use standard buses.
Where would high capacity transit get preferential treatment at signals?
Light rail and BRT would receive signal priority over auto traffic at most intersections when traffic conditions allow. At busy intersections or freeway off ramps it is more challenging for high capacity transit to receive signal priority, especially during peak rush hours. During rush hour in 2035, LRT is expected to be delayed 1 to 2 minutes and BRT delayed 6 minutes from estimated travel times due to high traffic volume at busy intersections.
Can local buses use the same exclusive right of way as the bus rapid transit or light rail vehicles?
Generally no, local buses cannot use right of way that is designated for light rail or bus rapid transit because of operational, safety and travel time considerations. There can be some exceptions to this when a shared transit way is developed. A shared transit way provides a paved section that allows local buses to use the dedicated high capacity transit lane. There are additional construction requirements and property impacts to develop a shared transit way.
There are currently three segments of the alignment that are being considered for shared transit ways:
- near the I-5 crossing between PCC Sylvania and Tigard Triangle areas
- in “the woods” section of Barbur north of Capitol Highway
- between Barbur Transit Center and “the woods”
The number of BRT vehicles needed to meet projected rider demand in the corridor would likely constrain the ability of local bus lines to also use a BRT busway as a shared transit way.
Will either of these options cut Barbur Blvd. down to one auto lane in either direction?
Current designs assume that two travel lanes in each direction would be maintained on Barbur Blvd. from its confluence with Naito Parkway to the Barbur Transit Center. Current designs only consider converting auto lanes to transit use where preliminary traffic analysis indicate it might be possible without negatively impacting traffic flow. Converting lanes may be possible on Barbur Blvd. south of the intersection with Capitol Highway near Barbur Transit Center. We will evaluate this in more detail during the Draft Environmental Impact Statement in 2017.
Would the transit-only lanes be added as new lanes to roads, or would existing lanes be converted to transit only?
In most cases, transit-only lanes are created by widening the roadway with a new lane, or using the center turn lane or under-utilized parking. There are a few locations in the current design where the traffic volumes are low and there appears to be excess capacity for autos. In these areas, additional study will be needed to determine if converting existing lanes to transit only can be accomplished without impacting traffic. In some cases, choosing to convert an existing lane to transit only, or running BRT in mixed traffic, can avoid property impacts associated with widening a roadway.
Relationship with existing bus service
How would either mode connect to existing TriMet lines?
More than a dozen existing local bus lines would connect to the high capacity transit line, including several lines at the Barbur and Tigard transit centers. Light Rail would interline -- or link up -- with either the existing Yellow or Green MAX line so that riders would not have to change MAX trains to cross the Willamette River. Because there are no existing BRT alignments on the downtown Portland Transit Mall, a BRT alignment would terminate at the north end of the Transit Mall near Union Station.
Will existing local bus lines in the area be changed?
The addition of high capacity transit in the area could free up operating hours for new bus lines and service improvements in the under-served areas of the corridor. With either BRT or light rail, some existing bus lines may be re-routed to optimize service and provide increased access to the high capacity transit line for areas that are currently not well served. The process to determine the details of how and which local bus routes will begin about two years before the project opens for service and include extensive public outreach.
Will light rail operate 7 days a week? 24 hours a day?
Either mode should have similar hours of operation as the existing MAX light rail system. Currently than means around 7 days a week, 20-21 hours a day.
Why is BRT not in 100% dedicated right-of-way? Where would the 20% mixed-traffic segments for BRT be located?
BRT will not run in 100% dedicated right of way because there are areas along the alignment where there is relatively less congestion and running BRT in mixed traffic in these areas does not significantly impact travel times. This approach can reduce unnecessary impacts or costs of building an exclusive busway.
BRT as envisioned in current concepts would run in mixed traffic along portions of Lincoln Street in SW Portland, along Barbur Blvd from Capitol Highway (east of Hillsdale) to Terwilliger Blvd, and through the Tigard Triangle. There are other mixed-traffic segments under consideration on Capitol Highway/49th Ave and on Barbur Blvd south of Crossroads (Barbur Transit Center).
Is BRT different from traditional “express buses” or “express routes”?
Yes, express buses typically only stop at transit centers and other major destinations. They sometimes run on the freeway and most only run during the weekday rush hours. The goal of BRT is to provide faster and more reliable travel times like express buses, but with service all day and on weekends and more frequent stations every ½ to ¾ mile.
What is the carbon footprint of both options?
Both light rail and BRT will reduce vehicle miles travelled in the region by providing options besides driving for every trip; that means less carbon pollution in the air.
Each option has energy impacts as well. Light rail vehicles are electric, but currently there are both hybrid and diesel BRT vehicles available and we don’t know which type of vehicles would be purchased for the SW Corridor. BRT transitway and vehicles have a shorter projected life span than light rail vehicles and trackways which means more frequent repaving and vehicle replacement for BRT. The Draft Environmental Impact Statement conducted in 2017 will calculate the impact of a high capacity transit line on regional driving and greenhouse gas emissions.
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