The on-demand transportation market is slowly but surely expanding beyond traditional ride-hailing to other modes of travel. One of the most promising new frontiers is app-based scooter sharing, a new but already fiercely competitive segment.

A number of separate reports from today indicate that Bird Rides Inc. and LimeBike Inc., two of this segment’s leading players, are both in the process of raising new funding rounds that could be worth a combined $450 million. LimeBike’s round accounts for the bulk of that sum.

Axios reported that the startup, which provides both scooters and bikes, is set to take in about $250 million from a group of investors led by Alphabet Inc.’s GV fund. Existing backers such as Coatue Management and Andreessen Horowitz are expected to chip in as well. The final value of the round could reportedly change since the deal has not yet been signed.

Bird, in turn, this morning submitted a regulatory filing authorizing the sale of up to $200 million worth of shares. TechCrunch, which obtained the paperwork from financial firm Lagniappe Labs LLC, detailed that the startup is offering 31.5 million shares for $6.15 each. The filing comes hot on the heel of a leak that suggested Bird is set to raise a $150 million round led by Sequoia Capital.

The investments could help significantly increase the number of electric scooters on the streets. Lime alone reportedly saw users take 1 million rides between May 5 and May 27. As for Bird, a newly surfaced job posting indicates that it’s seeking to expand its rival transportation network beyond the United States. Israel and the Netherlands are reportedly among the markets on the startup’s roadmap.

The on-demand transport market’s established players are also starting to look into city-friendly modes of travel. Word emerged last week that Lyft Inc. is on the verge of finalizing deal to acquire bike share startup Motivate Inc. for $200 million. And a couple months ago, Uber Technologies Inc. picked up a competing startup called Jump Bikes Inc. in a $250 million transaction.

But despite what the recent surge in activity might suggest, this is very much an emerging market that’s still experiencing growing pains. A number of cities such as San Francisco have recently imposed restrictions on electric scooter operators in a bid to address concerns over pedestrian safety.

Image: Lime