Bus* Definitions

Bus, express bus, BRT-lite and BRT can all be considered steps in a progression of incremental investment a transit line, gradually increasing the capacity, performance, and reliability. The fundamental goal over these improvements is to reduce the amount of time spent not moving, and increase the average speed while moving. The different steps are distinct based on the following factors:

• Right of Way

• Station Spacing

• Vehicle Characteristics

• Service Characteristics/Headway

• Intelligent Transportation Systems elements

Bu Rapid Transit

BRT is characterized by what Vuchic calls 'semi-rapid' guideway: barrier separated except at intersections, with limited sections of mixed traffic operations. BRT stations are substantial structures with passenger amenities, typically seating, off-board fare vending, trash-cans, and informational posters, capable of supporting level boarding for non-low floor vehicles. BRT vehicles may be regular or articulated vehicles with distinct appearance, either low-floor of platform-height boarding, and multiple door boarding. Service consists of regular headway throughout the day, and reliability maintained through the use of Intelligent Transportation System (ITS) features. The term BRT is often misapplied to a variety of inferior systems lacking many of these characteristics. Neither buses in dedicated lanes (busways) nor buses in HOV lanes represent BRT.

Express Bus

Express buses consist typically consist of long-distances routes with widely spaced stops, characterized by high speeds and comfortable travel.  Express buses typically operate in mixed traffic conditions, with minimal semi-rapid guideway. Examples include on-highway buses which operating in bus-only lanes for part of the route, but as a regular bus in mixed traffic within the central city. Many express buses provide only commuter service, operating for a limited number of hours each day. For the purposes of comparability, a non-commuter express bus is presumed [1]. 

FTA BRT & BRT-lite

For the purposes of funding, the Federal Transit Agency has defined systems with more than 51% dedicated (semi-rapid) guideway as BRT, and bus routes sufficiently meeting the other BRT standards as ‘BRT-lite’. BRT-lite is a bus with BRT-sauce: running in mixed traffic, but with limited stops and ITS features such as queue-jumps. No guideway requirements, which means BRT-lite can have anything from 0-50%. Outcomes are hence variable. 

ITDP does a better job of scoring BRTs. 

Incremental Investment

Bus, express bus, BRT-lite and BRT can all be considered steps in a progression of incremental investment in transit routes, gradually increasing the speed, comfort, and reliability, moving it toward a Rapid Transit standard. Because most of these investments are in operations (greater frequency, extended hours) they are reversible. In contrast, fixed-guideway transit investments such as those funded by the FTA typically represent a complete package of Rapid Transit elements, all at once: Dedicated guideway, signal priority, substantial stations to speed boarding, wider stop spacing, higher frequency and longer operating hours. They also come with a required guarantee of minimum service standards, to ensure that expensive capital investments are properly used. Because all of the improvements happen once, simultaneously, rather than incrementally, fixed-guideway rapid transit projects are perceived as development catalysts, capable of inducing development and revitalizing nearby areas. Streetcars represent the apogee of such a catalyst: providing a sudden increase in property values in a limited area, potentially spurring new, denser development.

Feasibly, in combination with appropriate revisions to zoning and parking requirements, a new light rail line could result in substantial additional multi-family development. Multifamily development is characterized by lower car ownership, and higher density residential is associated with great transit use (more people nearby the transit station generates more riders). The influx of residential population could then trigger a surge in demand for nearby retail and services, leading to the re-use or redevelopment of older buildings nearby. Following the exhaustion of available space nearby, the oldest and most-run down buildings will be torn down and replaced by new development. At sufficiently high densities, the combination of residential density generates sufficient street-life to represent an attractive walkable urban center, which attracts further residential develop, and additional retail and services.  Walkable mixed-use districts are generally considered to be highly attractive to both college-age populations and college educated professionals, and makes it possible for the region to compete to attract such populations. 

In contrast, incremental development will generate an incremental response: there will be no sudden upsurge in property values, the process of re-use, rehabilitation and redevelopment will be spread out over more years, and new development generated will be at a lower intensity. Incremental investment will never make the nearby area a ‘hot’ neighborhood. Correspondingly, the feedback loop of benefits to the area will be slower, the annual return on capital lower, and the whole area less attractive to developers. 

Fixed guideway rapid transit systems also offer an opportunity to attract ‘choice’ riders to the system, who elect to ride transit out of choice, rather than lack of alternatives. A fully implemented rapid transit route is exponentially better than it’s non-rapid equivalent due to the synergy between the elements: frequency and longer operating hours. Vehicles move faster and spend less time stopped, making is possible to provide the same amount of transit service with fewer vehicles. The combination of high frequency and dedicated guideway improve the reliability of the transit route. But the improved reliability of a central rapid transit ‘spine’ makes a transfer-based transit network feasible. It becomes possible to transition from a ‘hub-and-spoke’ based network toward a ‘fishbone’ arrangement of a rapid transit spine and bus ‘ribs’. Transfer-based transit networks are more efficient than centralized hub and spoke arrangements 

BRT vs. Traffic Lane 2

A traffic engineer friend of mine was good enough to point out some issues with my earlier post. 

One flaw in your math is that 1900 is not what arterial streets carry.  That is the “ideal saturation flow rate” which means if there were green lights all the time and no other interference, you’d probably measure 1900.  From there you apply reduction factors. The biggest factor is the green-time factor, which may be .6 on arterials, and .35 or so for collectors.  So .6*1900 = 1100.  But in truth, a road like the Provo BRT corridor will be closer to 750 or 800 vphpl.  Then you have the occupancy factor, which at peak times might be 1.3 or 1.4.  So say 800*1.4 = 1100 people/hr/lane, if carried in cars.

Taking this into account, I'll set forth another set of scenarios:

First set is a full BRT with 90 person on it. This is a bit flattering to BRT, because it assumes that the BRT is 'full' all the time.  It was a simplifying assumption. But the ideal BRT would move more people than the ideal traffic lane. (2439 vs. 1596).

But if we make that more realistic, and assume that the bus is half full during the peak hour (perhaps generous, but plausible), the numbers are much less flattering to BRT. Even at max buses/hour, it moves about as many as an actual travel lane (1215 vs. 1330/1064). However, during rush hour, 30 buses/hour compares favorably: 1215 vs. 1045/836. Hence, during rush hour, a BRT simply carries more persons than any traffic lane, even at 50% full.

 However, dropping the number of buses per hour significantly undermines that advantage. As 5 minute headway (12 buses/hour), a half-full BRT only has a capacity of 486, less than half of that for traffic lane, even during rush hour. Each bus would need to be full (90 people) during rush hour, to equal the capacity of a traffic lane. 

For automobile travel, passengers per vehicle is the real wild-card. As the chart shows, an HOV lane, even minimally loaded (2 persons) at its worse (1520) carries more persons than all the BRT systems except the full loaded BRT at 3 or 4 minute headways. 

This suggests a system of on-arterial HOV lanes would be a more effective strategy than BRT. But that will be the topic for a later post. 

BRT and Congestion

The principle of equilibrium assignment suggests that it is unlikely that congestion will change much on the corridor. If BRT successfully reduces automobile congestion on the corridor, travel will be faster in that corridor, and Down’s ‘triple convergence’[1] from alternate routes, times and modes will occur. In that context, the amount of congestion experienced by automobile drivers on the BRT corridor is unlikely to change significantly. However, from a system user perspective, the BRT may provide substantial benefits by actually reducing the amount of diversion (and out of direction travel) that is currently occurring. If this is so, it would be reasonable to expect a drop in volumes along the diversion corridors. It seems likely that the combination of ITS features and dedicated transit guideway will serve to increase the overall capacity of the roadway, and that a drop in traffic volumes on the diversion corridors is a reasonable hypothesis.

However, if congestion increases, a ‘triple divergence’ to alternate routes, times, and modes will occur. How much diversion occurs will depend on how attractive the alternatives are. Assuming no significant addition in roadway capacity on alternate corridors, diversion to alternate routes will result in a slight worsening in overall congestion. Diversion to alternate times will make the ‘peak hour’ longer (AKA ‘peak spreading’). Diversion to other modes may or may not reduce 

congestion.

Buses in general traffic lanes reduce capacity and increase congestion, a phenomenon well asserted both by the literature and by experience. The core principle of making transit ‘rapid’ is removing transit vehicles from general traffic lanes. This serves to both remove the effect of their operations on automobile traffic, and remove the effect of automobile congestion on transit vehicles.

As a thought experiment, assume the BRT is very attractive (in terms of time or cost), and attracts a large number of riders. This reduces automobile congestion along the alignment, making it faster. Drivers diverge from other modes and other routes, and the corridor becomes congested again. But only for automobiles--due to exclusive guideway, the BRT is less affected, and remains an attractive alternative. For drivers on the BRT corridor, there is no net benefit. For transportation system users, there are two classes of beneficiaries: BRT riders, and drivers on the diversion corridors.

A caveat to the benefits to drivers: The benefits to drivers on the alternate routes is going to get ‘lost in the noise’. They will be dispersed over a large number of roads, and reflected in small changes in the duration of peak periods, or in minor traffic volumes in a large number of roads. Provo-Orem is a rapidly growing metropolitan area, with substantial development taking place both north and south of the study area. Any minor advantage from the BRT to drivers will be rapidly eroded by additional land use changes.

A caveat to the benefits for riders: ‘rapid transit’ implies exclusive guideway; most BRT systems are only ‘semi-rapid’. While provided with transit signal priority, time separation (at intersections) provides a reasonable analogue to rapid transit conditions. However, the Provo-Orem BRT has only 51% exclusive guideway. Where the BRT lacks dedicated guideway, it will be exposed to the effects of congestion. In ideal circumstances, this guideway will be placed in the most effective location; where congestion is most intense. Congestion also tends to be greatest near intersections. Thus, roadways tend to be widest at intersections, where the road shoulder is used to provide turn lanes. Many worthwhile BRT projects have been subjected to the ‘death of a thousand cuts’; minor sacrifices made in the name of preserving automobile capacity (or worse:maintaining on-street parking).

However, given the number of routes that the also service parts of the BRT corridor[2], it is unlikely that all of the delay induced by local buses will be eliminated. In the context, it seems likely that the corridor will stay at a very similar level of congestion. 

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[1] https://escholarship.org/uc/item/3sh9003x#page-4

[2] http://www.rideuta.com/-/media/Files/System-Maps/2016/Utah-County-System-Map.ashx

Eugene BRT Guideway

I recently visited Eugene, Oregon to have another look at their 'Emerald Express' (EmX) Bus Rapid Transit (BRT) line. I was very impressed. I worked on a similar project for Ogden, Utah. Their solutions to a number of traffic engineering problems were very impressive, both in the quality of the engineering but also in the quality of the investment.

The EmX did well. Franklin Boulevard has a large grassy median, and the EMX carved a couple of bus-ways out of that.

Let me talk about guide-way a little bit. The EmX has a mix of guide-ways.

• Mixed Traffic
• Dedicated Lane (Center Running)
• Dedicated Lane (Side Running)
• Busway with concrete curbs
• Double Busway with concrete curbs

'Mixed Traffic' is the same as a normal bus. The western 50% of the EmX line is mixed traffic along a 6-lane wide arterial/state highway. It includes a couple of bridges, one of which is probably a quarter-mile long.

'Dedicated Lanes' is where the bus gets a 'bus only' lane.  In the EmX's case, rather than spending money annually to repaint the 'bus-only' lanes, it seems to have done them in concrete, while the rest of the street is asphalt. (I'm not sure if that was part of the original design, or an upgrade over time). Examining the aerial images, the bus lanes just seem to be re-done turn lanes, with some minor curb-side changes. The center-running were once a center-turn lane, and the side-running is the remainder of a right-turn lane and perhaps parking area. Examining different ages of aerial images (via ESRI and Google Earth), it appears that part of the dedicated lanes were originally Mixed Traffic, and only upgraded later on. Cars don't seem to have an issue crossing the bus lane to access curb-cuts for retail businesses.

I'm a little confused by the decision not to provide a dedicated lane in the Glenwood area between I-5 and the Willamette River.  There is certainly plenty of right of way. When building a fixed guide-way urban transit system, right of way is the killer. It's difficult to acquire, either through takings from property owners, or from the local Department of Transportation. While using DOT property seems simple, they may already have that pavement 'budgeted' for future planned increases in traffic, and loath to give it up today. Perhaps the speed of the road may have made doing so a safety hazard?

'Busway' is where there is a curb, so cars can't cross in front of the bus. It means the bus can travel much faster than in a dedicated lane, because a car cannot veer suddenly from an adjacent lane. Riding the EmX along the Busway was both exciting and a little alarming. I don't think I've ever been on a bus moving faster than 35 mph, and I think the EmX was pushing 60 mph on that segment. It makes about a quarter of the route. It has a middle section with two bus ways, side by side so that buses can pass one another. Most of the Busway is along Franklin Boulevard, which is a state highway with large grassy median, which provided the necessary right of way.

Operations
'Frequency' was excellent. The schedule indicated 15 minutes all day, with 10 minute peak times. The buses do not stack up, but neither do they linger. There is one 'stall' for the EmX at each end of it's route. When the arriving bus enters the station, the other bus departs.

The EmX does very well on average speed. The entire journey from boarding to de-boarding was under 20 minutes. Travel time was under 18. Google Earth tells me the route distance was about 3.78 miles. That gives an average travel speed of 12.6 mph.  (For reference, a 'slow' bus travels at an average 3.6 mph). The UTA TRAX, traveling a similar mix of guideway and distance (Arena to Center Point station) takes about 16 minutes, so it's not actually much faster...TRAX through downtown SLC is brutally slow.
  
Network
The EmX's success does not appear to be entirely contingent on mode. More, I think it is a matter of network design. Both ends of the EmX have substantial transit centers, which are also the terminus for multiple other buses, including a large number of double-articulated buses (functionally identical to the EmX).

9-Line BRT

Looks like UTA is planning to put some transit in place along 800 South/Indiana Avenue. Or so it appears from their ROW purchase plans. My best guess at the alignment for the BRT would be:

Start at 900 South Trax Station, West along 800 South, to Navaho Street.
Option A: Continue West along Indiana Avenue to Redwood Road
Option B: Head south along Navaho Street to Glendale 'Rose', then southeast to California Avenue.
-b1: Return to 1300 S. Trax
-b2: Continue West to Redwood Road.

And then hence south along Redwood Road, terminating at one of many TRAX stations, viz:

• Redwood Junction
• West Jordan City Center 
• Sandy Civic (at 10600 S. and State, following route 218)
• 114/118/Pioneer Road in Draper

Silver Line BRT

This is what Class I BRT (Bus Rapid Transit) looks like.

• Dedicated Right of Way
• Concrete Roadbase (Smoother rider).
• Limited Access/No Intersections
• Electrified Bus
• Articulated bus
• Substantial Stations
• Off-board fair collection
• Multi-door boarding