A scheme for optimizing segment sizes for an adaptive bitrate (ABR) streaming client engaged in a current ABR streaming session. In one implementation, a determination is made whether a wireless UE device executing the ABR streaming client is approaching a radio white spot area. If so, a video buffer of the ABR client is configured to preload a fixed number of segments having an adjusted size depending on the duration of the radio white spot area. The preloaded segments may comprise lower quality video segments, and as the wireless UE device exits the radio white spot area, the segment size and/or bitrates may be restored depending on the signal quality.