Alexander Dennis Enviro500
|Years of manufacture||2002 to present|
|Length||11.3 to 13.8 metres|
The Alexander Dennis Enviro500 is a tri-axle, double-decker transit and commuter bus. It was launched in 2002 by TransBus International and is part of the Enviro-series of buses. The Enviro500 is designed and built to meet European standards and the operating environment of Asia and North America. The Enviro500 is currently offered with traditional diesel propulsion, diesel-electric hybrid propulsion, and battery-electric propulsion options.
The chassis for the Enviro500 was developed from the Trident 3. The builder's plate on the early Enviro500 buses lists the chassis as "Trident E500". From 2004 to 2008, the Enviro500 body was built on the Volvo Buses B9TL chassis.
- 1 Asia Pacific design
- 2 European design
- 3 North American design
- 4 Specifications (On Enviro500 chassis)
- 5 Operators
- 6 Demonstrator Units
- 7 References
Asia Pacific design
The Enviro500 was first launched in Hong Kong, with Kowloon Motor Bus taking the first examples in 2002. Citybus and New World First Bus, Hong Kong's two other large bus companies, purchased their first Enviro500 buses in 2007. In addition to customers in Hong Kong, the Enviro500 was purchased by Dublin Bus in Ireland and First Glasgow in Scotland.
While the Trident 3 had a width of 2500 millimetres (98.4 inches), the body of the Enviro500 was wider at 2550 millimetres (100.3 inches). The bus was initially available in a length of 12 metres. A length of 11.3 metres later became available, with New World First Bus| (NWFB) and Kowloon Motor Bus (KMB) taking the first examples in 2009.
Buses for Hong Kong and other Asian cities have a fixed top deck rear window where the glass is broken for emergency egress. Whereas buses built for Dublin and Glasgow retained the traditional window frame with push-out egress. In addition later model buses for Asia would have the emergency door on the lower deck replaced by a glazed panel that can be broken.
The original styling of the Enviro500 was shared with the single-deck Enviro300. In late 2003, both were revised with a slightly different lower front and rear fascia.
In 2012, Alexander Dennis launched a new version of the Enviro500 for the Asia Pacific region known as the Enviro500 MMC (major model change). This version of the Enviro500, in addition to following the exterior restyle that was first introduced in North America, uses a new chassis with the drivetrain off-set to the left. The new chassis configuration along with a new staircase design have increased the seating capacity to 90. Changes in materials and parts design lead to a reduction of weight as well. These include an aluminum radiator and lighter polymer panels.
The Asia Pacific Enviro500 MMC was restyled at the end of 2015 with a similar aesthetic to the Enviro400 MMC. This design is also in-line with the updated Enviro500 introduced to North America a year earlier. Buses built for operators in New Zealand continue to use the pre-facelifted body design, however, mainly due to the narrower vehicle width compared to the Asia-Pacific or North American versions.
Singapore concept bus
In 2015, the Land Transport Authority (LTA) commissioned Alexander Dennis as well as MAN to each design a bus specifically for their service area. The Singapore-specific Enviro500 made its debut in March 2016 and was displayed at various events around Singapore, culminating with display at the Singapore International Transport Congress and Exhibition in October 2016.
The bus is 13 metres long and has three doors. Inside, the bus has two staircases; one near the front and one behind the rear wheels. The bus shown to the public was an unpowered mock-up, likely due to the need to redesign the engine compartment to accommodate the rear staircase and rearmost door. The bus seats a total of 72 passengers and provides USB charging ports on board.
The actual unit was rolled out in March 2021, the design would be full flat floor to compare with MAN ND323 3-door unit with some steps on the rear doorway , meanwhile the drive axle was moved from the center to the rear to accommodate the drivetrain components relocating to the right. 
In September 2015, Alexander Dennis announced that they received an order for 19 Enviro500 buses for Swiss operator PostAuto. The buses were delivered in 2017, launching the Enviro500 in continental Europe. One of these buses was also shown at the year's Busworld trade show in Kortrijk, Belgium.
Berliner Verkehrsbetriebe (BVG) of Berlin, Germany trialed an Enviro500 in October 2015. Three years later in October 2018, Alexander Dennis announced that BVG placed an order for 70 Enviro500 buses. The contract allows for the purchase of up to 430 buses. The first two pilot buses were delivered in October 2020.
The European Enviro500 is 13-metres long and 4-metres tall. It is available with 2 or 3 doors as well as one or two staircases. The buses built for Berlin are 13.8-metres long, 4.06-metres tall, and seat 80 passengers.
North American design
In 2004 Alexander Dennis introduced a version of the Enviro500 for the North American market. It had a modified body with a lower height. It used a redesigned fuel tank that enabled the straight staircase to be moved forward. Unlike the Enviro500 overseas, the North American version lacked a rear window. This area, instead, had a black gloss-effect rectangular panel with larger circular tail lights on either side.
In late 2007, Alexander Dennis announced that a 12.8 metre long version of the Enviro500 would be made available in 2008. GO Transit was the first customer to receive this version. The Regional Transportation Commission of Southern Nevada later took delivery of 12.8 metre length Enviro500 buses with two staircases.
At the 2011 APTA Expo in New Orleans, Alexander Dennis launched a redesigned look to the Enviro500 based on the front styling of the Enviro400. A lower, "Go-Anywhere" height option was launched as well, with OC Transpo and GO Transit among the first customers.
The lower height at 4.1 metres was only available with the 12.8 metre length to make up for a reduction in seating capacity. Unlike the standard height model, the rear row of seats is over the rearmost wheel with the fuel tank behind. The fuel tank had to be relocated due to the dropped body height. The door beside the last passenger window is used for maintenance access.
A redesign for the 2015-model year was introduced at the 2014 APTA Expo in Houston. It features an exterior similar to the Euro 6 Enviro400 and shares a little bit of the interior aesthetic. The fuel tank was modified to allow for more rear passenger space while maintaining the "Go-Anywhere" height. In addition, the drivetrain is offset to the left like the post-2012 Asia Pacific design.
Alexander Dennis produced another version of the Enviro500 in 2016. The "Super-Lo" Enviro500 was developed at the behest of Metrolinx and has a lower height than the "Go-Anywhere" version. At 3.9 metres, it is able to fit in GO Transit's Hamilton, Yorkdale, York Mills, and Union Station bus terminals. The "Super-Lo" Enviro500 is also 13.8 metres long and has the rear half of the lower deck reserved for luggage.
Metrolinx agreed to purchase 253 "Super-Lo" buses over a five-year period with an option for 150 more. As part of the agreement, a chassis assembly facility was constructed in the Greater Toronto and Hamilton Area.
Vancouver purchased 57 Enviro500 MMC for use on their suburban routes. The first bus was in service by the end of October 2019.  32 were delivered until 2020 with an order of an additional 25 currently on hold.
Specifications (On Enviro500 chassis)
|Length: 11.3 m (37 ft), 12 m (39 ft 4 in), 12.9 m (42 ft), 13.8 m (45 ft 4 in)|
|Width: 2520 mm (8 ft 3 in) or 2580 mm (8 ft 5 in)|
|Height: 3.9 m (12 ft 10 in), 4.0 m (13 ft 1 in), 4.06 m (1 ft 4 in), 4.1 m (13 ft 6 in), 4.2 m (13 ft 9 in), or 4.3 m (14 ft 1 in)|
|Gross Vehicle Weight: 26,500 kg (56,656 lbs)|
|Cummins ISL9 8.9 litre, 330 or 380 hp||EPA 2010, EPA 2013, GHG14, EPA 2016||2010-2017|
|Cummins ISLe 8.9 litre, 340 or 380 hp||Euro 4, 5 & 6||2006-2017|
|Cummins ISM 10.6 litre, 330 hp||EPA 2004, EPA 2007||2004-2010|
|Cummins ISMe, 10.6 litre, 335 hp||Euro 3||2002-2006|
|Cummins L9 8.9 litre, 330 or 380 hp||GHG17||2017 onwards|
|Cummins L9 8.9 litre, 340 or 370 hp||Euro 6-C||2017 onwards|
|Mercedes-Benz OM 936 7.7 litre, 354 hp||Berlin Euro 6-D||2020 onwards|
|Allison B500R||2007 onwards|
|Voith D864.6||2017 onwards|
|ZF 6AP1700B||2010 onwards|
|Dana NDS 80LF deep drop I beam, 17,640 lbs capacity, 55° lock angle||2002-2014|
|ZF RL75A deep drop beam axle, 16538 lbs (7500kg) capacity, 47° lock angle||2012 onwards|
|Dana Drop centre 28,665 lbs capacity,||2002-2014|
|ZF AV 132 drop centre, 6.2:1, 5.74:1, 5.13:1, 4.54:1 ratios, 26460 lbs (12000 kg) capacity||2012-2017|
|ZF AV 133 drop centre, 6.2:1, 5.74:1, 5.12:1, 4.53:1 ratios, 26460 lbs (12000 kg) capacity||2017 onwards|
|Dana T75ULF drop centre, 16,535 lbs capacity||2002-2014|
|ZF RL75A deep drop beam axle, 16538 lbs (7500 kg capacity, 10° lock angle, steering||2012 onwards|
|Front: Knorr Bremes disc brakes|
|Rear and tag: Dana S Cam brakes|
|Thermo King TDD-C|
|Thermo King TDD-M1|
|Thermo King TDD-M2|
|Thermo King TDD-M4|
- BC Transit
- Victoria Regional Transit System - Victoria, BC
- Coast Mountain Bus Company (TransLink) - Metro Vancouver, BC
- GO Transit - Golden Horseshoe, ON
- OC Transpo - Ottawa, ON
- Strathcona County Transit - Sherwood Park, AB
- Cruise Victoria
- Berliner Verkehrsbetriebe (BVG - Berlin (on order)
- CLP Group employee shuttle (operated by Citybus)
- Kowloon Motor Bus (KMB)
- Long Win Bus
- Mass Transit Railway (MTR)
- New World First Bus (NWFB)
- Dublin Bus - Dublin
- Metrobús - Mexico City
- Howick & Eastern - Auckland
- NZ Bus - Auckland
- Transports publics de la région lausannoise - Lausanne
- First Glasgow - Glasgow
- AC Transit - Alameda & Contra Costa County, CA
- Community Transit - Snohomish County, WA
- Gray Line New York - New York, NY
- Gray Line San Francisco - San Francisco, CA
- Gray Line of Washington Washington, DC
- Hawaii County Mass Transit Agency (Hele-On Bus) - Hawaii County, HI
- Maui Bus - Maui, HI
- Open Top Sightseeing San Francisco - San Francisco, CA
- Open Top Sightseeing Washington - Washington, DC
- Regional Transportation Commission of Southern Nevada (RTC Transit) - Las Vegas, NV
- San Luis Obispo Transit (SLO Transit) - San Luis Obispo, CA
- Sound Transit - Snohomish, King & Pierce Counties, WA
- Unitrans - Davis, CA
- Western Contra Costa County Transit Authority (WestCAT) - Contra Costa County, CA
|7/2004||SFET222184GN11721||Cummins ISM||Voith D864.3E||
|2007||SFET132106GN11861||Cummins ISM||ZF 6HP602C|
|2007||SFET455257GN11888||Cummins ISL9||Allison B500R|
|8/2011||SFET40738BGN12390||Cummins ISL9||Allison B500R|
|10/2012||SFET7E730CGN12518||Cummins ISL9||Allison B500R||
|8/2014||SFET9K749EGN13476||Cummins ISL9||Allison B500R||
|6/2014||SFET9K748EGN13484||Cummins ISL9||Allison B500R||
|G517/1||2017||13m, 3-door European development vehicle|
- New-generation Enviro500: Lighter, more fuel-efficient and set to raise the bar (Press release). 06 November 2012. Alexander Dennis. Retrieved on 15 February 2013.
- 100 Three-door Double-Decker Buses Procured by LTA Land Transport Guru 25 April 2019
-  Alexander Dennis 26 April 2019
- 3-Door Buses compared: ADL Enviro500 and MAN A95 Land Transport Guru -3-Door Buses compared: ADL Enviro500 and MAN A95 10 March 2021
- Alexander Dennis Enviro500 (3 Door) Land Transport Guru 10 March 2021
- “First ADL Enviro500 double deckers arrive in Berlin.” Press release. NFI Group, 21 October 2020.
- Alexander Dennis set to unveil stylish new look for double deck range (Press release). Alexander Dennis Limited. 31 August 2011. Retrieved on 01 September 2011
- Alexander Dennis steps up a gear with new-look double deck and $150m business wins (Press release). Alexander Dennis Limited. 5 October 2011. Retrieved on 7 October 2011
- Metrolinx bus purchase to improve service and create jobs (press release). 24 November 2014. Metrolinx. Retrieved on 07 February 2015.
- Alexander Dennis RHD Enviro500 Spec Sheet (Euro 5). Alexander Dennis Limited. Retreived on 26 February 2011
- Technical Specifications Enviro500 for PostAuto. Alexander Dennis Limited.
- Alexander Dennis LHD Enviro500 Spec Sheet (EPA 2004). Alexander Dennis Limited. Retreived on 26 February 2011
- Alexander Dennis RHD Enviro500 Spec Sheet (Euro 3). Alexander Dennis Limited. Retreived on 26 February 2011
- Berlin Enviro500 technical specifications.