Another reason Tu B'Av is celebrated is that on that day, the roads to Jerusalem were opened after more than 200 years of being closed to prevent the Jews from celebrating their pilgrimages and feasts.
On Tu B'Av, Hosea ben Eilah opened the roads to Jerusalem. Upon the division of the Holy Land into two kingdoms following the death of King Solomon in the year 2964 from creation (797 BCE), Jeroboam ben Nebat, ruler of the breakaway Northern Kingdom of Israel, set up roadblocks to prevent his citizens from making the thrice-yearly pilgrimage to the Holy Temple in Jerusalem, capital of the Southern Kingdom of Judea. These were finally removed more than 200 years later by Hosea ben Eilah, the last king of the Northern Kingdom, on Av 15, 3187 (574 BCE).
Will Tu B'Av be the long awaited day that the roads will open, allowing God's chosen people, His Bride to enter the New Jerusalem, the Tabernacle of God, the Holy City, the City of God, the Celestial City, the Heavenly Jerusalem? Here we have the Jews, after the death of their very wise king, waiting 200 years to be able to go to Jerusalem to celebrate their Holy Feasts. For the believers in Christ, we have our very wise and all-knowing King Jesus, nearly 2000 years of waiting since His death and resurrection, finally being allowed to go to the New Jerusalem to worship Him! Will the roadblocks be removed on Tu B'Av???