Sunday, 25 August 2024

In Defence of the 'Tram-style' Designed Single-deck Buses

Photo by Liverpool City Region Combined Authority

I'm aware that on social media there have been objections to the 'tram-style' buses, whether they are articulated (bendy) or not, which also includes 'trackless trams' Autonomous Rail Rapid Transit (ART).

Recently, the Liverpool City Region Mayor unveiled a tram-style bendy bus (Van Hool Exqui.City) leased from Translink in Northern Ireland for demonstration of a new bus rapid transit service in Liverpool, which is part of the Steve Rotheram mayoral manifesto commitment. I'm also aware there's a similar concept in Brisbane, Australia, where they expect to launch a new rapid transit service on 21st October 2024, branded as Brisbane Metro.


As many people said on social media that it is a 'bus', the fact that it has a rounded, sloped front makes it look similar to a tram, which is one of the major aspects of improving safety standards for buses.

One of the earliest known examples of a single-deck bus with a sloped front end is the Optare Delta.

The sloped front ends of the bus are part of Transport for London's (TfL) Bus Safety Standards and to reduce serious injuries in collisions with vulnerable road users (VRU).

Here's a page from TfL's Bus Safety Standard executive summary.

I'm not an expert in the engineering or manufacturing fields, but this has become a requirement as part of the new Bus Vehicle Specifications for London. Certain buses throughout the United Kingdom, Ireland and certain parts of the world have also included some bus safety standard features.

Taking a look at Bus Vehicle Specifications Version 2.5 (obtained by a Freedom of Information request):

4.6 Partner Protection
TfL are currently conducting further research and assessment of data taken from service conditions to develop the requirements, assessment protocols and guidance notes for Partner Protection and ensure their suitability. As such this section provides an understanding of the current expectations, it is however subject to change.

Bus front ends have been identified as one of the key contact points of the vehicle in collisions with vulnerable road users (VRU). Several different safety features are required to minimise the injury potential in those collisions.

In all assessments of these features, the physical or virtual test vehicle to be assessed shall be configured at its maximum ride attitude from the ground plane, with its mass in running order (the nominal unladen vehicle and driver mass), tyres inflated to manufacturer recommended pressures and vehicle suspension set to normal running conditions (as specified by the OEM for a speed of 25 mph).

4.6.1 VRU Frontal Crashworthiness: Minimum Geometry
This requirement only applies to new vehicles entering the fleet from 2021 as per the Bus Safety Roadmap for new build buses

All bus front ends are required to have a geometric design that both improves protection for VRUs during the primary impact of a collision and reduces the risks of VRUs being subsequently run over.

All buses shall have a front-end geometry that complies with the minimum bus front end geometry requirements for both vertical rake angle and horizontal curvature.

4.6.2 VRU Frontal Crashworthiness: Enhanced Geometry
This requirement only applies to new vehicles entering the fleet from 2024 as per the Bus Safety Roadmap for new build buses

All buses shall be assessed in accordance with the bus front end geometry test and assessment protocols (Attachment 39), reporting vertical rake and horizontal angles for each test point, bus front end geometry envelope compliance status, the front end geometry score (FEGS), the bus front end geometry star rating and the number of safety performance criteria scores with a value of 0 for each bus model or bus model variant (as appropriate).

All buses shall have a front-end geometry compliant with the bus front end geometry envelope, which is defined by the following boundary conditions:
• Vertical rake angles for all measuring points at all test positions (P1-P5) shall be no less than 4 ° and no greater than 23°.
• Horizontal angles for all measuring points at the outboard test positions (P1 and P5) shall be no less than 20° and no greater than 33°.
• Horizontal angles for all measuring points at the inboard test positions (P2 and P4) shall be no less than 11° and no greater than 18°.

There are also requirements in the Bus Vehicle Specifications, which include windscreen wiper protection.

Here are the attachments to Bus Vehicle Specifications v2.5, which show the illustrations of the sloped front of the bus.

This is one of the reasons why London has been at the forefront of improving accessibility, design, and safety for their bus fleet. This includes the glazed staircase on double-deck buses, a design cue from the New Routemaster that is seen in many towns and cities in the UK and abroad.

Irizar ie Tram for Route 358
I would like to mention that I have researched through TfL's consultation reports and that there have been numerous requests for 'tram-style' bendy buses. And yes, we are still waiting for the non-articulated Irizar ie Tram, to enter passenger service on route 358.

Some people on social media have been saying that they should use trams. I agree, but there are advantages and disadvantages when it comes to building new tram lines. I have detailed this in my article: Bus lanes and priority measures make a good case for new tram lines.

It's time to think outside the box and be more creative about how to improve public transport and make travel more attractive. I have published an article explaining this, which includes bus route branding, bus designs, routes, etc.

To help increase capacity and improve accessibility, I suggested that the Superloop and the East London Transit should use tram-style bendy buses to make the Superloop more of a Bus Rapid Transit along with increasing bus priority measures, which is useful for the emergency services to improve their response times as they get stuck in heavy traffic.

I have suggested that the London Passenger Transport Area should be reinstated to enhance cross-boundary bus services, especially reviving the Country Buses and Green Line express bus services. I also suggested that the Speedbus proposal from the 1970s should be revived.

It's time for a brand new chapter in improving public transport. Here are more of my suggestions linked below.

Suggestion: I Believe It’s Time for a New Regional Transport Body for the South East of England? (This will require change to the legislation in Parliament).

I Believe TfL Should Reform The Travelcard Agreement To Offer Smart Flexible Ticketing Options

Suggestion: The Administrative Divisions in England should be reformed and restructured to simplify responsibilities

I invite you to follow me on X by searching for @CLondoner92 or by clicking on the direct link to my X page here. I'm also on BlueSky and Mastodon.

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