A key target has been Republican mayor Kevin Faulconer.

While San Diego's city hall continues to dally on the regulation of so-called e-scooters and other transportation devices cluttering local streets and sidewalks, hard evidence has emerged from Los Angeles about the surging tide of injuries connected to the new technology.

The latest report comes from researchers at UCLA, who surveyed Los Angeles emergency rooms run by the university for "standing electric scooter injuries," with sobering results.

"In this study of a case series, 249 patients presented to the emergency department with injuries associated with electric scooter use during a 1-year period, with 10.8% of patients younger than 18 years," says the January 25 paper by Tarak K. Trivedi, Charles Liu, and Anna Liza M. Antonio.

"The most common injuries were fractures (31.7%), head injuries (40.2%), and soft-tissue injuries (27.7%)."

"Only 10 riders were documented as wearing a helmet, constituting 4.4% of all riders," the report notes. "Twelve patients (4.8%) had physician-documented intoxication or a blood alcohol level greater than 0.05%."

In addition to clinical work, the research team took to L.A. streets and sidewalks to document the wayward conduct of scooter users. "A total of 193 scooter riders were observed during 3 public observation sessions, and the following unsafe riding practices were observed: no helmet use (182 riders [94.3%]), tandem riding (15 riders [7.8%]), and failure to comply with traffic laws (18 riders [9.3%]). Additionally, many riders were observed to be riding on the sidewalk (51 riders [26.4%]), where scooter use is prohibited.

Conclusion: "Riders share roads with fast-moving vehicular traffic but appear to underestimate hazards." As a result, researchers say, new laws are likely needed to curtail the urban onslaught.

"While riders of electric scooters in California are required to be at least 16 years old by state law and 18 years old by company rental agreements, we found that 10.8% of electric scooter injuries were in patients younger than 18 years. This suggests that current self-enforced regulations imposed by private electric scooter companies may be inadequate."

Further research, the report says, is needed to "examine the effects of bikeway availability and speed limits, which may modify the occurrence of injuries associated with electric scooter use. It would also be meaningful to characterize the costs incurred by patients and the health care system from trauma associated with electric scooter use."

Adds the study, "Among scooter riders, the most common mechanisms of injury were fall (183 riders [80.2%]), collision with an object (25 riders [11.0%]), and being hit by a moving vehicle or object (20 riders [8.8%]). "

Though no similar studies have yet been published regarding San Diego, streets and sidewalks here have become testbeds for venture capitalists seeking to exploit the scooter and e-bike craze. The emerging industry is spending heavily on lobbyists and contributions to city politicos in an attempt to forestall potential regulations.

A key target has been Republican mayor Kevin Faulconer. In November, LimeBike parent Neutron Holdings of San Mateo forked over $12,299 to fund the mayor's charity, One San Diego, through which he and wife Katherine Stuart hand out free Thanksgiving turkeys in poorer neighborhoods of the city.

Bird, which paid San Diego lobbyist Clarissa Reyes Faulcon $15,000 in the final quarter of last year per a January 25 disclosure, complained to ABC News that the UCLA study's scope was inadequate.

"In the case of this study, Bird did not have the opportunity to work with the study’s authors or to collaborate with them, and we find the report to be very limited," Paul Steely White, director of safety policy and advocacy, said in an email.