Abu Hanzalah says that I asked Sayyiduna Ibn Umar (may Allah be pleased with them both) about the prayer during travel. He replied: "During travel, the prayer is two rak'ahs." We said: "But now there is safety and security everywhere, while Allah Almighty says: 'If you are in fear?'" He replied: "This is the Sunnah of the Prophet (peace and blessings be upon him)."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 6194
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد محتمل للتحسين من أجل أبى حنظلة .