Alternative Wheelers

Alternative Wheelers

How Effective?

Summaries of key findings from several research reports are given below. Further details of the studies reviewed, including methodology and findings, and links to the reports, are given in the References section.

Specialised pedal cycles

Road safety issues related to standard pedal cycles are dealt with in the following syntheses:

  • Pedal cyclists;
  • Cycling infrastructure.

‘RRCGB: notes, definitions, symbols and conventions’ provides the following definition for pedal cycles:

  • Pedal cycles include tandems, tricycles and toy cycles ridden on the carriageway. From 1983 the definition includes a small number of cycles and tricycles with battery assistance with a maximum speed of 15mph.

(DfT, nd)

Alternative pedal cycles (DfT, 2011a) include:

  • Low step-through bikes;
  • Standard tandems;
  • Recumbent cycles (also known as ‘crank forward’ cycles);
  • Trikes for one person;
  • Trikes for two people allowing both riders to pedal;
  • Trikes for two people where only one rider pedals;
  • Handcycles; and,
  • Quads.

The results of a data collection event taking place on a shared use cycle path in the US confirmed the great diversity in the operating characteristics of various road and trail user types. The authors concluded that consideration should therefore be given to the following when designing cycle infrastructure:

  • Design Speed - Recumbent cyclists had the highest observed 85th percentile speeds of 18 mph, less than American Association of State Highway and Transportation Officials (AASHTO’s) minimum design speed.
  • Horizontal Alignment - Most users did not reduce their speeds for turning radii greater than 16 m.
  • Stopping Sight Distance - A recumbent cyclist in the 85th percentile requires a stopping sight distance of 32.7m on wet pavements, less than the AASHTO value.
  • Vertical Alignment/Crest Vertical Curves - Recumbent bicyclists had a required length of a crest vertical curve of 46.7 m, less than the AASHTO value.
  • Signal Clearance Intervals - Five-second clearance intervals would provide insufficient time for most users (85th percentile users) to clear a five-lane (18.3m wide) junction.

(FHWA, 2004)

Other vehicles

Other vehicles are types of vehicle not falling into any of the main categories (e.g. car, HGV). According to STATS20 (DfT, 2011b) examples are:

  • Ambulances;
  • Fire engines;
  • Motor caravans;
  • Quad bikes;
  • Pedestrian controlled vehicles with a motor;
  • Refuse vehicles;
  • Road rollers;
  • Mobile cranes;
  • Tower wagons; and,
  • Army tanks.

Also included are miscellaneous types of vehicles without a motor, other than pedal cycles. Examples are:

  • Vehicles drawn by an animal;
  • Invalid carriages that are self propelled without a motor; and,
  • Pedestrian controlled vehicles without a motor which are normally used on the road (e.g. street barrows).

Emergency vehicles

Police vehicles are not specifically mentioned in the ‘other motor vehicles’ definition but can have safety concerns similar to those related to ambulances and fire engines. Other emergency vehicles which can use blue lights include: bomb disposal vehicles; mountain rescue vehicles; prison vehicles with escorts; coastguard vehicles; and, blood and organ donor vehicles. However, it should be noted that blue lights do not, in all cases, mean an exemption from speed limits.

  • Police pursuits can be extremely dangerous to parties involved in the pursuit (police officers and suspected law violator) and the general public.

  • Recent statistics and some high profile incidents in the United Kingdom have highlighted a rise in police-driver RTIs.

  • In 2002 the UK Police Complaints Authority published a report investigating RTIs involving police vehicles. They reported that in the 9 months preceding the publication of the study there were 30 fatalities resulting from police pursuits. Compared with the 9 deaths that occurred in the 12-month period covering 1997–1998, this represents an increase of 344 per cent in police pursuit fatalities over a period of time during which road usage only increased by 4.7 per cent.

  • There has been relatively little research undertaken on the behavioural factors that impinge on police driving with a view to reducing the number of RTIs.

  • An eye movement and hazard perception study was conducted by Crundall et al (2003) using a driving simulator. Although police drivers did not report more hazards than the other participants (who belonged to either an ‘aged matched’ or ‘novice’ control group) reported, they had an increased frequency of electrodermal responses (response to stress or anxiety measured in the skin), a greater visual sampling rate and spread of search while viewing dangerous clips.

  • However all drivers had a reduced spread of search in night-time pursuits because of the focusing of overt attention.

  • Police drivers are generally more aware of their surroundings. The research has identified areas of concern regarding visual attention in prolonged hazardous situations and at night.

(Crundall et al, 2003)

In 2001 TRL assessed the effectiveness of vehicle designs, the potential for proposed changes in design, and identified areas where cost-effective safety improvements might be possible for other motor vehicles, including fire tenders and ambulances. Fatal RTIs which occurred between 1993 and 1995 were assessed.

  • The database contained information on 11 RTIs involving emergency vehicles, 5 involving fire tenders and 6 involving ambulances. These RTIs resulted in 13 fatalities of which 11 were car occupants.

  • 3 of the 5 RTIs involving fire tenders occurred when the fire tender was travelling through a red light; the cars were struck in the side.

  • A system which sensed the approach of emergency vehicles on call and automatically changed traffic signals to give them priority would have avoided all of these RTIs.

(Knight, 2001)


Recently there has been demand for mini motorbikes, quad bikes and other similar vehicles. Some of the bikes are capable of speeds in excess of 40mph. RoSPA has highlighted concerns that there is a lack of understanding regarding safety issues and recognised safe places to ride.

  • Before buying mini-motorbikes and similar machines people should:

    • Check for local safe and legal riding places;

    • Be willing to transport the bike to and from such places; and,

    • Invest in appropriate safety equipment and training.

(RoSPA, 2010)

Refuse collection vehicles

One of the greatest safety issues associated with refuse collection vehicles (RCVs) is reversing as it is difficult for drivers to have complete visibility of the road environment behind the vehicle. Reversing aids such as mirrors, CCTV cameras, high visibility warning lights, alarms and detectors can help reduce RTIs involving refuse collection workers and the general public.

  • Reversing causes a disproportionately large number of moving vehicle RTIs in the waste/recycling industry.

  • Injuries to collection workers or members of the public by moving collection vehicles are typically severe or fatal.

  • Unlike many other workplaces complete control often cannot be exercised over the environment during collection because of factors such as:

    • Street geography;

    • Street furniture;

    • Other vehicles;

    • Pedestrians; and,

    • Weather

  • People at risk of being struck by reversing vehicles include the following:

    • Loaders working at the vehicle;

    • Pedestrians, including:

      • Children (who might not understand the risks);

      • People with impaired sight and hearing (who might be unaware of the activity and its risks, or may not be able to avoid the moving vehicle);

      • People with limited mobility, (who may not be able to avoid the moving vehicle); and,

      • Other road users such as motorists, cyclists and horse riders who might unexpectedly appear during reversing operations.

  • Examples of risk reduction measures include the following:

    • Liaison with householders and customers to re-locate waste and recycling collection points;

    • Use more appropriate vehicles;

    • Change collection methods;

    • Plan collection times, to avoid:

      • Busy times on major roads;

      • Shopping areas during opening hours;

      • School start and finish times; and,

      • Reversing into the direction of the sun.

  • Wherever possible, risks can be reduced by eliminating reversing and reducing distances reversed. Many organisations have concluded that they will always use reversing assistants (banksman) unless it is not safe to do so.

  • Drivers should have effective vision from the collection vehicle. The driver’s direct vision through the windscreen (area swept by the wipers) should not be obstructed by items such as stickers, clothing, newspapers or additional equipment such as CCTV monitors.

  • High-visibility warning lights/beacons should be fitted to the front and rear of RCVs and other vehicles that operate in a similar way.

  • Reversing alarms should be fitted and be clearly audible at the side and rear of the vehicles.

  • Reversing detectors can provide additional warning of objects or people entering the reversing zone.

  • It is recommended that local authorities and waste management companies research and assess available products for best performance as technological advances have been rapid in this area.

(HSE, 2006)

Agricultural vehicles

According to STATS20 (DfT, 2011b) this category will include agricultural tractors (whether or not towing), mobile excavators and front dumpers.

Road rollers, mobile cranes, tower wagons and army tanks are categorised as other vehicles but are similar in nature to the construction vehicles coded as agricultural vehicles.

In 2001 TRL assessed the effectiveness of vehicle designs, the potential for proposed changes in design and identified areas where cost-effective safety improvements might be possible for other motor vehicles including agricultural vehicles. Fatal RTIs which occurred between 1993 and 1995 were assessed.

  • According to STATS19 there were 195 fatal RTI involving at least one ‘other motor vehicle’ (OMV) between 1993 and 1995.

  • Agricultural vehicles were by far the most common (41 RTIs) vehicle type.

  • It would appear that agricultural tractors are considerably more hazardous for motorcyclists than other types of OMV.

  • Fifty-nine per cent of all RTIs involving tractors occurred on an ‘A’ road, with a further 20 per cent on unclassified roads, 17 per cent on a ‘B’ road and 4 per cent on a ‘C’ road.

  • Tractor usage is seasonal, therefore, it would not be unreasonable to expect peaks for RTIs to follow seasonal use. Improving lighting and/or conspicuity such that agricultural vehicles are more readily identified in the dark, and direction signals are more easily seen was considered to have saved around one in five of the car occupant fatalities.

  • Improving the side and rear visibility from the tractor such that overtaking cars might be more easily seen by the tractor driver is estimated to be capable of reducing car occupant fatality by ‘one or two’ over the study period.

  • The use of seatbelts in tractors could have been of significant benefit in reducing injuries from fatal to serious.

(Knight, 2001)

Electric Personal Assistive Mobility Devices and other users of shared use cycle paths

Electric Personal Assistive Mobility Devices (EPAMDs), such as Segways, are becoming popular in the United States and some European countries. However, these devices are classed as motor vehicles in the UK and are not permitted to be used on pavements. However, they cannot be used on the road as they do not comply with road traffic law. Therefore their use in the UK is limited to private land, but only with the land owner’s permission.

Cycling infrastructure such as shared use cycle paths (pedal cycle and pedestrian use) are often referred to as non-motorised facilities or trails in the United States. A number of researchers have studied the implications of a more diverse range of users on these facilities.

  • With the increasing variety of emerging users comes the question of whether the US is designing and building suitable facilities. Many jurisdictions throughout the United States have adopted the American Association of State Highway and Transportation Officials (AASHTO) Guide to the Development of Bicycle Facilities as a standard for shared use trail design and other facilities used by non-motorised travellers.

  • The US Department of Transportation, Federal Highway Administration conducted data collection events involving 811 participants to better understand the physical dimensions and operational characteristics of an increasingly diverse group of trail and roadway users including:

    • Kick scooters;

    • Inline skates;

    • Hand cycles;

    • Recumbent bicycles;

    • EPAMD (e.g. Segway); and,

    • Mobility assistive devices (wheelchairs, powered wheelchairs and powered scooters).

  • The results confirmed the great diversity in the operating characteristics of various road and trail user types. Therefore, consideration should be given to these alternative operating characteristics when designing cycle infrastructure. For example the 85th percentile inline skater had a 1.5 metre sweep width, which is wider than the AASHTO recommended width for bike lanes.

  • These findings suggest that design guidelines may need to be revised to incorporate the needs of emerging trail users. The results of this study can be used to help professionals adequately design roadway and shared use path facilities to meet the operational and safety needs of this growing group of users.

(FHWA, 2004)

  • Litman and Blair (2010) identified that there is an increasing variety of people using alternative modes (of transport) that are requesting permission to operate on non-motorised facilities (such as footpaths, cycle lanes, paths and trails), including Personal Mobility Devices (PMDs) small wheeled devices that provide personal mobility such as wheelchairs, skateboards and skates and Electric Personal Assistive Mobility Devices (EPAMDs) such as Segways.

  • It can be difficult to categorise these devices since they have diverse features and uses.

  • It is increasingly important for transport planners and public officials to decide how non-motorised facilities should be managed, including where and when specific modes and activities should be allowed, the rules each should follow, and how such rules should be promoted and enforced.

  • Speed regulation is important for PMD facility management because space requirements and risk increase with speed.

  • Effective education and enforcement are important for non-motorised facility management. Signs, brochures and maps can help educate users concerning how to share facilities, how non-motorised traffic rules are enforced, and how to report violations.

(Litman and Blair, 2010)

  • In a pilot study conducted in a closed indoor track, technical tests demonstrated that in normal use situations, Segways were stable, operated quietly and smoothly, and gave users the feeling of being in control of the vehicle.

(Lavallée, 2004)

  • Experimentation with Segways under actual operating conditions on public roadways involving 143 users, in 3 cities in Canada, was conducted in 2006. No incident or serious injury, nor any Segway/pedestrian RTIs or physical interference, was reported during the evaluation, where distances totalling more than 9,000 km were covered. The only incidents reported involved the user only. The frequency of such incidents may diminish as users gain driving experience.

  • It was concluded that EPAMDs being driven on sidewalks, cycle paths and cycle lanes where speed is limited to 30mph will have little impact on user safety and still less on the safety of pedestrians, cyclists, motorists and other pedestrian route users.

  • Sidewalks were the only type of pedestrian route where the acceptability of EPAMDs was at all in question. EPAMD traffic was found quite acceptable on cycle paths and roadway shoulders.

(Castonguay and Binwa, 2006)

Gaps in the research

In general there is a lack of research on the majority of vehicle types discussed in this synthesis. It is difficult to understand the number of RTIs involving each vehicle type discussed because the statistics are in most instances grouped together as ‘other vehicles’.

Due to the relatively small numbers of ‘alternative wheelers’ used there is very little robust evidence of safety issues regarding each vehicle type.


  • Date Added: 03 Apr 2012, 08:14 AM
  • Last Update: 11 Dec 2017, 04:04 PM