Arlington County is planning to spend millions of dollars on a nostalgic-looking streetcar that will cause massive traffic backups on Columbia Pike and help drive out the small businesses and moderately priced apartments that give the Pike its funky urban charm.

The trolley, which will run down Columbia Pike from Pentagon City and then veer over to Skyline Mall on Route 7, will supposedly reduce traffic congestion and improve air quality while it spurs economic development. But not even some Arlington environmentalists are buying it.