Although Ermua currently has direct connections to Bilbao via lines A3926 and A3916, the council points out that both originate or terminate in other municipalities. This frequently results in buses arriving already at high occupancy levels, forcing passengers to stand or even preventing access to the service at certain times.

The draft project includes a specific reinforcement between Bilbao and Ermua, but the City Council believes a structural solution is needed. Mayor Beatriz Gámiz states that the town requires a "direct and stable" connection to the capital, a common destination for many residents for work, academic, health, or administrative reasons.

Therefore, the allegation proposes incorporating a line with origin and destination in Ermua into the final design, which would guarantee sufficient seats and improve service quality.