A new study has found that ride-sharing services result in much more pollution than other kinds of private and public transportation.
Ride-sharing trips also draw passengers away from more environment friendly methods of travel, like public transportation, walking or biking, the study found.
Several studies in recent years have suggested that ride-sharing services like Uber and Lyft can worsen traffic problems in cities, which continue to have high rates of private vehicle ownership.
The new study, carried out by the not-for-profit group Union of Concerned Scientists, represents an attempt to center on how ride-sharing services affect pollution. The research examined the effects of ride-sharing services on seven of America's largest cities.
Overall, the researchers reported that ride-sharing trips now result in an estimated 69 percent more climate pollution on average than the trips they displace. The study notes that the same passengers could have chosen to travel by bus, train, bike, scooter or on foot.
One of the big reasons they give for this result is that ride-sharing vehicles are often driven with no passengers in the car. This happens when drivers are either waiting for rider requests, are on the way to pick up passengers or are driving in between pickups.
This situation, known as "deadheading," takes up about 42 percent of all ride-sharing driving activity, the study found. The researchers said that deadheading results in about 50 percent more carbon dioxide than one person driving in a private vehicle.
Both Uber and Lyft do offer a choice of a "pooled" ride, which involves drivers picking up additional riders during the same trip.
The study urges services like Uber and Lyft to work to increase the amount of pooled rides. It also urges the two companies to increase the number of electric vehicles on the road and to improve connections to public transportation centers.
Both Uber and Lyft have said in the past that most studies on the subject overstate the effects of their services on pollution. They have noted that the majority of vehicles on the road belong to private individuals or companies.
1.center on 聚焦，关注
He did fine work-the discussion these days is centered on the second or third decimal place of that number.
2.result in 造成，导致，结果是
Next, we need to understand the circumstances that resulted in these notifications.
这项新研究是非营利组织忧思科学家联盟发起的，该研究着力于找到拼车服务对污染的影响方式 。该研究审视了美国7个大城市拼车服务的影响 。
总体来说，这些研究人员发现，拼车造成的气候污染平均比其他出行方式高69% 。该研究发现，选择拼车的乘客本来也可以选择乘坐公交车、火车、自行车、滑板车或者步行 。
研究人员给出这个结果的一个重要原因是用于拼车的车辆通常里面都没有乘客 。这种情况之所以会发生都是因为司机在等待接单，或者是在去乘客的路上，或者是在两单之间奔波 。
该研究发现，这样的情况占所有拼车活动的近42% 。研究人员表示，这样的情况产生的二氧化碳比使用私人交通工具产生的二氧化碳高50% 。
优步和来福车都表示过去大多数关于该主题的研究都夸大了他们对污染的影响 。这2家公司还表示，路上的大多数车辆都属于私人交通或者属于公司 。