Background Many of the burgeoning megacities in developing countries have witnessed poorly planned urban sprawls. The absence of a coherent mass public transport system encourages the acquisition of inexpensive motorcycles for commuting and this has distorted the traffic mix. In Karachi the proportion of motorcycles on the road has risen from 34% of registered vehicles to 55% over the past decade. We have sought to assess the impact of this on road use fatalities by analysis of data captured by ongoing road traffic injury surveillance based in 5 city hospitals.

Methods The recorded road-use deaths were those dying within 30 days of being admitted to hospital and included cases brought dead to the EDs or the mortuaries of the hospitals. The case information included gender, age, number of vehicles involved in the crash, road-user type (motorcycle rider or pillion rider), helmet use and injury scoring.

Results During 8 years, 2007–2014, motorcycle occupants accounted for 3901 of the 9192 fatalities and over the study period these increased from 36% to 53% of the recorded road deaths (p < 0.001). 69% of them were aged 35 years or less. Though most motorcycle collisions resulting in death involved heavy commercial vehicles, 185 fatalities resulted from motorcycle to motorcycle collisions. Of the 3253 pedestrian fatalities recorded, a motorcycle had struck 19% of them. Of the 2179 instances where a cause could be ascribed to the motorcycle fatality, over speeding was reported in over 50% and the top 6 roads for motorcyclist fatalities were signal-free corridors.

Conclusions An escalating socio-economic tragedy is being played out in the urban centres of many developing countries by the juxtaposition of poor public transport and availability of inexpensive motorcycles. Our study suggests that while the implementation of mass transit schemes are awaited, strategies that segregate traffic and reduce speeds should be prioritised along with strict enforcement of helmet laws.