Angkutan

Angkutan atawa transportasi (Basa Inggris:transportation, umum digunakeun di Amerika Sarikat), nyaéta pindahna jalma jeung barang ti hiji tempat ka tempat séjénna. Istilah ieu asalna tina basa Latin trans, hartina meuntas, jeung portare, hartina mawa.
Widang angkutan mibanda sababaraha aspék nu gampangna bisa dibagi jadi 3 bagian: infrastruktur, tutumpakan, jeung operasi. Infrastruktur kaasup jaringan angkutan (jalan, karéta rél, penerbangan, kanal, pipelines, jsb.) nu digunakeun, ogé kaasup tempat ngumpulna atawa terminal (kayaning bandara, stasion karéta, terminal beus, jeung labuan). Tutumpakan umumna anu bolak-balik dina jaringan, saperti mobil, karéta, pesawat terbang. Nu kaasup kana operasi nyaéta saperti rambu lalu lintas jeung ramp meter, railroad switch, kontrol lalu lintas awang-awang, jsb, ogé pulisi, nu lianna saperti kumaha sistim béaya (saperti maké tol atawa pajeg béngsin dina kasus angkutan jalan tol).
Sacara luas bisa disebutkeun, disain jaringan mangrupa widang dina téhnik sipil jeung tata kota, disain tutumpakan di widang rékayasa mékanis jeung bagian husus saperti nautical engineering jeung aerospace engineering, sarta operasi biasa husus, bisa ngagunakeun "pendekatan" operations research atawa rékayasa sistim.
Moda nyaéta kombinasi jaringan, alat, jeung operasi, kaasup leumpang, sistim angkutan jalan, angkutan rél, angkutan kapal laut, jeung penerbangan modérn.
Angkutan jeung komunikasi duanana silih gantikeun jeung silih lengkepan (substitutes and complements). Malah kamajuan dina widang komunikasi bisa ngagantikeun angkutan, kayaning ngaliwatan telegraf, telefon, faks, atawa surélék, batan didatangan jelemana hiji-hiji, nyata yén cara komunikasi kitu ngalahirkeun interaksi nu leuwih gembleng, kaasup interaksi antarpribadi. Pertumbuhan angkutan teu mungkin mun euweuh komunikasi, nu penting pisan pikeun sistim angkutan nu maju. Ti rél karéta nu rék diliwatan ku karéta ti dua arah dina jalur tunggal, nepi ka lalu lintas awang-awang nu merlukeun nyaho lokasi pesawat di awang-awang. Jadi, geus kapanggih yén kamajuan nu hiji bakal ngarojong kana kamajuan nu séjénna.
There is a well-known relationship between the density of development, and types of transportation. Density is defined as aréa of floorspace per aréa of land. As a rule of thumb, densities of 1.5 or less are well suited to automobiles. Densities of six and above are well suited to trains. The range of densities from about two up to about four is not well served by conventional public or private transport. Many cities have grown into these densities, and are suffering traffic problems. Personal rapid transit might fill this gap.
Land uses support activities. Those activities are spatially separated. Péople need transport to go from one to the other (from home to work to shop back to home for instance). Transport is a "derived demand," in that transport is unnecessary but for the activities pursued at the ends of trips. Good land use keeps common activities close (e.g. housing and food shopping), and places higher-density development closer to transportation lines and hubs. Poor land use concentrates activities (such as jobs) far from other destinations (such as housing and shopping).
There are economies of agglomeration. Beyond transportation some land uses are more efficient when clustered. Transportation facilities consume land, and in cities, pavement (devoted to streets and parking) can éasily exceed 20% of the total land use. An efficient transport system can reduce land waste.
Angkutan mangrupa konsumén énergi nu utama, lolobana maké hidrokarbon. Mun ngadurukna teu sampurna, balukarna jadi polusi. Sanajan tutumpakan di Amérika Serikat geus beuki bersih ku ayana aturan lingkungan. Low-pollution fuels can reduce pollution. The most popular low-pollution fuel at this time is liquified natural gas. Hydrogen is an even lower-pollution fuel.
Another tack is to maké vehicles more efficient, which reduces pollution and waste by reducing the energy use. If electricity can be gotten to the vehicle, electric motors are the most efficient of all. Another method is to generate energy using fuel cells, which are two to five times as efficient as the heat engines traditionally used in vehicles. A trivial, but very effective method is to stréamline ground vehicles, which spend up to 75% of their energy on air-resistance. Another method is to recycle the energy normally lost to braking, but this léads to a more complex vehicle.