WASHINGTON, Oct 26 (Reuters) - Google executive Prabhakar Raghavan on Thursday detailed challenges the search and advertising giant faces from smaller rivals, describing efforts to avoid becoming "the next road kill."

Raghavan testified at the ongoing antitrust trial in the suit brought by the U.S. Justice Department and a coalition of state attorneys general, alleging Alphabet's Google unlawfully abused its dominance in the search-engine market to maintain monopoly power.

Raghavan, asked about a 1998 article about Yahoo!'s dominance of search at the time, said he was acutely aware rivals from Expedia.com to Instagram to TikTok competed for users' attention.

"I feel a keen sense not to become the next road kill," said Raghavan, a senior vice president at Google who reports to chief executive Sundar Pichai.

Raghavan said Google had some 8,000 engineers and product managers working on search, with about 1,000 involved in search quality.

Raghavan's description of Google struggling to stay relevant clashed with the Justice Department's depiction of a behemoth that broke antitrust law to retain dominance of online search and some aspects of advertising, including paying an estimated $10 billion annually to smartphone makers and wireless carriers to be the default search engine on devices. Google's share of the search engine market is near 90%.

Raghavan said that Google faced different types of competitors, including general search where they compete against Microsoft's Bing and specialized search engines, such as the travel website Expedia.com. He described Amazon.com as one of the companies that he worried most about competing against.

Young people have begun doing searches on the video-sharing app TikTok and other social media apps, he said. "Where young people go, older people follow," he said.

Asked about the expression "Grandpa Google," Raghavan said "unfortunately, yes" he had heard it. "Grandpa Google will help with things like homework but when it comes to interesting things, they go elsewhere," he said.

The trial began in September and will conclude in mid-November. (Reporting by Diane Bartz Editing by Tomasz Janowski)